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Volume 88 (1980)
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Volume 88, Issue 4
Displaying 1-39 of 39 articles from this issue
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Norio HAYASHI, Motoko TERASAWA, Goro KIKUCHI1980 Volume 88 Issue 4 Pages 921-926
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe half-life of δ-aminolevulinate (ALA) synthase in the liver mitochondria of allylisopropyl-acetamide-treated rats was estimated to be about 35min, taking advantage of the observation that hemin strongly inhibits the translocation of ALA synthase from the liver cytosol into the mitochondria. ALA synthase accumulating in the liver cytosol in allylisopropylacetamide-treated rats is rapidly translocated into mitochondria with a half-disappearance time of about 20min, but does not appear to undergo degradation until it is translocated into mitochondria. A study with an ALA synthase-specific IgG revealed that the decrease in the ALA synthase activity in the liver mitochondria observed after the administration of cycloheximide or hemin effectively paralleled the decrease in the amount of immunologically reactive protein, providing further evidence that ALA synthase is rapidly degraded in the mitochondria.View full abstractDownload PDF (417K) -
Yoh SANO1980 Volume 88 Issue 4 Pages 927-932
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe concentration dependence of reduced scattering intensity of fractionated bovine lens α-crystallin was observed in the presence of various concentrations of calcium ions, using the usual angular light scattering technique. The intensity of scattered light at zero angle per unit concentration of α-crystallin increased sharply with increase of the calcium ion concentration, reaching a maximum at about 50-60mM, and then decreasing rapidly at calcium levels above 60mM. This indicates that reaggregation and deaggregation of α-crystallin occur in the presence of calcium ions. Application of light scattering analysis showed the inverse intensity of the scattered light to have a significant upward curvature with increasing α-crystallin concentration. The third virial coefficient determined from this upward curvature was very high at low calcium concentrations, and then decreased monotonously with increase of the calcium ion concentration. It was almost zero over the high concentration of 50mM Ca2+View full abstractDownload PDF (465K) -
Hiroshi NAKASHIMA, Shio MAKINO1980 Volume 88 Issue 4 Pages 933-947
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe state of association of bovine Band 3, which is a major intrinsic protein of erythrocyte membranes, was examined in nonaethyleneglycol dodecyl ether (C12E9) solution by ultracen-trifugation, gel filtration, gel electrophoresis and cross-linking studies. The molecular weight of bovine Band 3 was 107, 000±5% as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. When Band 3 was purified in C12E9 solution with the aid of 2, 3-dimethylmaleic anhydride (DMMA), which is a known dissociating reagent for peripheral proteins from erythrocyte membranes and for Band 3-Band 4.2 complex, the protein was present as a monomer and was not oxidatively cross-linked. On the other hand, DMMA-untreated Band 3 was present as oligomeric forms composed mainly of the dimer and tetramer, and the oligomer in C12E9 was as susceptible to oxidative cross-linking as Band 3 in ghosts. The oligomeric form apparently retained a more ordered conformational state than the monomeric form. These results indicate that the bovine Band 3 oligomer is a stable form in C12E9, but the present result showing the coexistence of dimer and tetramer in C12E9 contrasts with the reported observation that human Band 3 is present as a stable dimer in a nonionic detergent, Triton X-100.
It was shown that polyacrylamide gradient gel electrophoresis in the presence of C12E9 gave better resolution of the associated species of Band 3 than ultracentrifugation or gel filtration, and this method made it possible to determine the Stokes radii of Band 3-C12E9 complexes. This result suggests the usefulness of electrophoretic methods in the presence of nonionic detergent for studies of the state of association of other membrane proteins.View full abstractDownload PDF (1139K) -
Kinya KOIZUMI, Yoshimasa ITO, Jun OKUDA, Tatsuzo FUJII, Keiko TAMIYA-K ...1980 Volume 88 Issue 4 Pages 949-954
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPhospholipase A activities in plasma membranes (PMs), isolated from rat ascites hepatoma cells (AH 130, AH 130FN, AH 7974, and AH 7974F), were determined and compared with those in PMs isolated from normal rat livers (neonatal, resting adult, and regenerating adult livers). All the PMs had a hydrolyzing action on 1-acyl-2-[14C]oleyl-sn-glycero-3-phosphoethanolamine but not on similarly labeled phosphatidylcholine. After hydrolysis, the radioactivity was recovered in both the lyso derivative and the free fatty acid produced. Thus, the presence of phospholipases A1 and A2 in the PMs, with an optimal pH around pH 9, was demonstrated. In all the hepatoma PMs, the phospholipase A2 activity was greatly reduced or almost lacking, whereas in the PMs from normal resting and growing livers strong phospholipase A2 activity was detected equally but with a specific activity higher than that of phospholipase A1.
Triton X-100 treatment had an activating effect on phospholipase A1 but an inhibitory effect on phospholipase A2 of the resting liver PMs, while the same treatment was inhibitory for both the phospholipase, Al and A2, activities of the hepatoma PMs.View full abstractDownload PDF (462K) -
I. Characterization of Native and Proteolyzed “4S” Estrogen ReceptorsAkira MURAYAMA, Fumio FUKAI, Tadahiko HAZATO, Tadashi YAMAMOTO1980 Volume 88 Issue 4 Pages 955-961
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe estrogen receptor (ER) was separated from the cytoplasmic components of the cow uterus through successive gel filtrations of the cytosol in the presence of antipain, a protease inhibitor. The partially purified ER (designated as native “4S” ER) sedimented at 4.5S under both hypotonic (low salt) and hypertonic (0.4 M KCl) conditions. The molecular weight of native “4S” ER was estimated to be approximately 82, 000 with a Stokes radius of 44 A. If purification was performed in the absence of antipain, native “4S” ER was very labile to a protease present in the cytoplasm. The modified ER (designated as modified “4S” ER) sedimented at 4.5S like native “4S” ER, but had a smaller Stokes radius (35 A) and a smaller molecular weight (65, 000). In the presence of 0.4M NaSCN, native “4S” ER remained intact, but modified “4S” ER dissociated and gave a fragment which retained the estradiol binding site. This fragment sedimented at 2.9S and had a Stokes radius of approximately 24 A (molecular weight, approximately 29, 000). In the presence of Ca2+ ions and in the absence of antipain, the native ER was modified by the cytoplasmic protease to give ERs sedimenting at 3.8-4.5S. The presence of a cytoplasmic component which specifically binds with native “4S” ER to give “8S” ER under hypotonic conditions was indicated. Modified “4S” ER was unable to bind with this component.View full abstractDownload PDF (491K) -
II. Characterization of a Cytoplasmic Factor which Binds with Native “4S” Estrogen Receptor to Give “8S” Estrogen ReceptorAkira MURAYAMA, Fumio FUKAI, Tadahiko HAZATO, Tadashi YAMAMOTO1980 Volume 88 Issue 4 Pages 963-968
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPartial purification and characterization of a cytoplasmic component of cow uterus, which specifically binds with native “4S” estrogen receptor (ER) to give “8S” ER was carried out. The component was designated as “8S” ER-forming factor [(“8S”ER)-FF]. (“8S”ER)-FF did not bind estradiol by itself. The Stokes radius of (“8S”ER)-FF was estimated to be approximately 51 A. (“8S”ER)-FF sedimented at around 6.9S in sucrose gradient centrifugation under hypotonic conditions. The molecular weight and frictional ratio of (“8S”ER)-FF were calculated to be 145, 000 and 1.47, respectively. (“8S”ER)-FF was degraded by trypsin treatment, but was not affected by DNase or RNase. The Stokes radius of “8S” ER was estimated to be approximately 68 A. The molecular weight and frictional ratio of “8S” ER were calculated to be 225, 000 and 1.69, respectively. “8S” ER was estimated to be a 1:1 complex between native “4S” ER and (“8S”ER)-FF. It was estimated that in the cow uterine cytosol, there was at least a 3-fold molar excess of (“8S”ER)-FF over the amount of “4S” ER. (“8S”ER)-FF inhibited both the Ca2+-dependent and -independent modifications of native “4S” ER by the cytoplasmic protease.View full abstractDownload PDF (359K) -
III. Molecular Constitution of Estrogen Receptor-Binding FactorsAkira MURAYAMA, Fumio FUKAI, Tadashi YAMAMOTO1980 Volume 88 Issue 4 Pages 969-976
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS“8S” estrogen receptor-forming factor [(“8S”ER)-FF], a cytoplasmic factor of cow uterus, which binds specifically with native “4S” estrogen receptor (ER) to give “8S” ER under hypotonic (low salt) conditions was dissociated in the presence of 0.4M NaSCN into two kinds of subunits designated as component A and component B. Characterization of components A and B was performed. The Stokes radius and molecular weight of component A were estimated to be around 37 A and 58, 000, respectively. Those of component B were estimated to be around 18.5 A and 13, 700, respectively. These components did not bind with estradiol, and underwent molecular assembly depending on the salt concentration of the medium to give complexes, which, in turn, bound with native “4S” ER to give ERs with higher sedimentation coefficients. Component A [designated as “5S” ER-forming factor, (“5S”ER)-FF] bound with native “4S” ER to give “5S” ER, which was stable under hypertonic (0.4M KCl) conditions. Under hypotonic conditions, component B formed a hexamer [designated as “6S” ER-forming factor, (“6S”ER)-FF], which bound with native “4S” ER to give “6S” ER. “4S” ER was dissociated from “6S” ER under hypetonic conditions. (“8S”ER)-FF was shown to be a 1:1 complex of component A and the hexamer of component B. These factors [(“5S”ER)-FF, (“6S”ER)-FF and (“8S”ER)-FF] which bind specifically with native “4S” ER to give ERs with higher sedimentation coefficients were designated as estrogen receptor-binding factors (ERBFs).View full abstractDownload PDF (509K) -
A Model Reaction of Specific Peptide Substrate Activated by Binding to the EnzymeKazuhiko IKEDA, Shigeru KUNUGI1980 Volume 88 Issue 4 Pages 977-986
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAs a model reaction of the enzyme-bound activated peptide substrates in proteinase-catalyzed hydrolysis, the α-chymotrypsin-catalyzed hydrolysis of three acylimidazoles (trans-cinnamoyl-imidazole, indoleacryloylimidazole, and furylacryloylimidazole) was studied, especially as regards the acylation process. The complicated pH-dependences of the reactions, due mainly to the existence of the protonated forms of these acylimidazoles, were analyzed based on a reaction scheme considering the so-called inactive monomeric enzyme and the dimeric enzyme. The intrinsic reaction parameters for individual species were evaluated.
The acylation through the mono-protonated enzyme-substrate complex (ESH) reflects the rate of attack by Ser-195 Oγ on the carbonyl carbon of acylimidazolium, where the formation of the possible tetrahedral intermediate is rate-determining. The acylation via the non-protonated enzyme-substrate complex (ES) is intermediate between those of esters (as regards the single bond character of the cleaved linkage) and of amides (with respect to the proton transfer as a key process of the acylation). This was confirmed by the observation of acceleration of the acylation rate upon addition of external proton donors. Based on these results, the mechanism of acylation in peptide substrate hydrolysis is discussed.View full abstractDownload PDF (754K) -
Fumio TAKEUCHI, Hidetsugu OTSUKA, Yukio SHIBATA1980 Volume 88 Issue 4 Pages 987-994
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSKynureninase [L-kynurenine hydrolase EC 3. 7. 1. 3] has been purified 614-fold from rat liver cytosol. The purification procedure involved pH treatment, ammonium sulfate fractionation, Sephadex G-100 gel filtration, DEAE-Sepharose CL-6B chromatography, extraction with 40% saturated solution of ammonium sulfate and hydroxyapatite chromatography. The enzyme was found to be homogeneous by the criteria of disc gel electrophoresis, SDS-gel electrophoresis and sucrose gradient centrifugation. The enzyme was obtained as a holoenzyme which showed an absorption maximum at 420 nm. In the absence of pyridoxal 5-phosphate (PLP) the enzyme was dissociated into an apoenzyme. The isoelectric points of holoenzyme and apoenzyme are 5.7 and 6.1. Sucrose gradient centrifugation and SDS-gel electrophoresis gave molecular weight estimates of 95, 000 and 55, 000, respectively. The optimum pH shifted to higher pH with increase in the concentration of PLP. The Michaelis constants were determined as follows: kynurenine, 240 μM; 3-hydroxykynurenine, 13 μM; PLP, 0.1-1.7 μM. The maximum velocity for 3-hydroxykynurenine was 11 times higher than that for kynurenine at pH 7.7. This enzyme can be regarded as a 3-hydroxykynureninase type enzyme.View full abstractDownload PDF (587K) -
III. Chemical Modification of the Envelope of Sendai VirusHiroaki JIZOMOTO, Hitoshi ARITA, Kenji SUGITA, Jun'ichi KAWANAMI, Kosa ...1980 Volume 88 Issue 4 Pages 995-999
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTreatment of Sendai virus with p-azidophenyl-6-chloro-6-deoxy-β-D-glucopyranoside (APG) caused chemical modification of the viral envelope under UV irradiation, which did not affect the hemagglutinin activity of the virus but inhibited the hemolytic activity. Also, the transfer of phospholipid from the viral envelope to chicken erythrocytes was measured using a spinlabel technique by electron spin resonance (ESR). In this experiment, the phospholipid transfer was depressed by the treatment with APG under the conditions which inhibited the hemolytic activity of the virus. These results suggest that APG bound covalently to lipid may disturb the specific interaction between the protein and the lipid of the viral envelope, resulting in the inhibition of the hemolytic activity. The effects of APG on the hemolysis and phospholipid transfer were compared with the results for the concanavalin A- and amphotericin B-treated viruses.View full abstractDownload PDF (353K) -
Fumiaki ITO, Yukito MASAMUNE1980 Volume 88 Issue 4 Pages 1001-1007
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSRNA polymerase of Shigella sonnei rif purified through DEAE-Sephadex A-50 could not initiate the synthesis of DNA using phage fd DNA as a template. A protein which could complement the polymerase to initiate the synthesis of DNA was recovered from the DEAE-Sephadex A-50 column separately from the RNA polymerase. There is apparently a protein which is required to synthesize a primer RNA for the synthesis of DNA other than the components of RNA polymerase holoenzyme of Shigella sonnei rif. The protein seems to be specifically required for the initiation of DNA synthesis and to have little effect on the synthesis of RNA.View full abstractDownload PDF (521K) -
Kaichi KIDA, Takashi NISHIO, Takako YOKOZAWA, Katsuya NAGAI, Hiroshi M ...1980 Volume 88 Issue 4 Pages 1009-1013
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe circadian change of gluconeogenesis in the liver in vivo in fed rats was studied. Gluconeogenesis in the liver in vivo was determined by measuring the rate of synthesis of 14C-labeled blood glucose derived from a 14C-labeled substrate, such as lactate, pyruvate or an amino acid injected into nephrectomized rats. Gluconeogenesis in the liver from all substrates examined except glutamine was higher at 8:00 P. M. than at 8:00 A. M. in correspondence with the circadian rhythm of the activity of hepatic phosphoenolpyruvate carboxykinase. These data indicate that hepatic gluconeogenesis shows a circadian change in response to changes in nutritional conditions in vivo.View full abstractDownload PDF (367K) -
Eiji SHIMADA, Go MATSUMURA1980 Volume 88 Issue 4 Pages 1015-1023
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSaturated and unsaturated hyaluronate oligosaccharides were prepared from human umbilical cord hyaluronic acid by partial digestion with bovine testicular and Streptomyces hyaluronidase, respectively. After treatment with Streptomyces hyaluronidase, the distribution of degradation products from these oligosaccharides was determined.
Octasaccharides, either saturated or unsaturated, were substrates of the minimum size. Tetra- and hexasaccharides were not degraded further and remained as final products. This indicates that at least four succeeding N-acetylhyalobiuronosyl residues were required for this enzymatic degradation. Since unsaturated oligosaccharides were more susceptible to this enzyme than saturated ones of the same polymerization degree, and inner glucosaminidic linkages were cleaved in preference to those at the outermost sites, some groups adjacent to this segment seemed to influence the susceptibility of the oligosaccharide to this enzyme.View full abstractDownload PDF (615K) -
Shuji KAWATA, Shuji TAKAYAMA, Kazuto NINOMIYA, Satoru MAKISUMI1980 Volume 88 Issue 4 Pages 1025-1032
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn aminopeptidase B from porcine liver was purified about 2, 000-fold by ammonium sulfate fractionation and a series of chromatographies on hydroxyapatite, DEAE-cellulose, Sephadex G-150, hydroxyapatite and DEAE-Sepharose columns. The purified preparation was homogeneous on polyacrylamide gel electrophoresis. The molecular weight of the enzyme was about 58, 000 as determined by gel filtration on Sephadex G-100 and disc gel electrophoresis in the presence of sodium dodecyl sulfate. The enzyme exhibited maximum activity at pH 7.5 for the hydrolysis of L-arginine β-naphthylamide at 25°C. The enzyme was labile to prolonged warming and freezing. The enzyme was markedly stimulated by chloride ion, and was inhibited by Cu2+, Zn2+, Cd2+, Hg2+, Pb2+, and metal chelating agents. p-Chloromercuribenzoate was an uncompetitive inhibitor of the enzyme with a K1 value of 1.8×10-6M. The enzyme was inhibited by 1, 10-phenanthroline, and the inhibition was of the mixed type with a K1 value of 1.9×10-4M but activity was restored by the addition of Zn2+, Co2+, and Fe2+.View full abstractDownload PDF (574K) -
Toshio UCHIUMI, Kazuo TERAO, Kikuo OGATA1980 Volume 88 Issue 4 Pages 1033-1044
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSProtein-protein neighbors in rat liver 60S ribosomal subunits were investigated by using two bifunctional imidoesters; dimethyl suberimidate (DMS) and dimethyl 3, 3'-dithiobispropionimidate (DTP).
1. Complexes cross-linked with DMS were separated by two-dimensional acrylamide/urea gel electrophoresis. Each complex in the gel was labeled with 125I (1) and was cleaved into the original monomeric protein constituents by ammonolysis. The products were analyzed by two-dimensional acrylamide/urea gel electrophoresis, followed by radioautography of the stained gel. Eight protein pairs are proposed according to our numbering system (2): L1-L3 (L3-L5), L2-L21 (L4-L26), L5-L13 (L7/L7a-Ll5), L5-L34 (L7/L7a-L36), L6-L34 (L8-L36), L6-L32 (L8-L35), L12-L32 (L13/LI3a-L35), and L18-L27 (LI8a-L27/L27a). The designations according to the proposed uniform nomenclature (3) are given in parentheses.
2. Complexes cross-linked with DTP were analyzed by acrylamide/SDS diagonal gel electrophoresis (4), and the molecular weights of the complexes and their components were determined. The monomer components of cross-linked pairs were labeled with 125I in the gel, and identified by two-dimensional acrylamide/urea gel electrophoresis followed by radioautography. Six pairs are proposed; L1-L5 (L3-L7/L7a), L1-L6 (L3-L8), L5-L19 (L7/L7a-L21/L23/L23a), L13-L15 (L15-L14), L13-L16 (L15-L19), and L23-L27 (L30-L27/L27a).
3. Two pairs which were formed by protein-protein interaction without the use of crosslinking reagents were identified as L2-L4 (L4-L6) and L4-L30 (L6-L29).View full abstractDownload PDF (3683K) -
Yoko FUJITA, Takashi SHIMAKATA, Takashi KUSAKA1980 Volume 88 Issue 4 Pages 1045-1050
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTwo forms of enoyl-CoA hydratase (hydratases I and II), which are different from each other in substrate specificity, were found in a crude extract of Mycobacterium smegmatis. Hydratase I was more active with crotonyl-CoA as a substrate than with decenoyl-CoA, whereas the reverse was the case for hydratase II. Hydratase I was purified 688-fold to homogeneity with a yield of 14.5 % from the crude extract. Its molecular weight was estimated to be 16, 000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 30, 000 by gel filtration, suggesting that the enzyme is dimeric. Hydratase II was also partially purified. The Vmax of hydratase I decreased progressively with increase in the carbon-chain length of the substrate from 2, 488 units/mg for crotonyl-CoA to 154 units/mg for hexadecenoyl-CoA, whereas the Km values for crotonyl-CoA (82 μM), decenoyl-CoA (91 μm), and hexadecenoyl-CoA (105 μm) were similar. Both hydratases were inhibited by acetoacetyl-CoA and pCMS, but not by N-ethylmaleimide or monoiodoacetate.View full abstractDownload PDF (906K) -
Takashi SHIMAKATA, Yoko FUJITA, Takashi KUSAKA1980 Volume 88 Issue 4 Pages 1051-1058
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS2-Enoyl-CoA reductase was purified 150-fold from the crude extract of Mycobacterium smegmatis. The purified reductase required NADH, but not NADPH, as a reductant and catalyzed the reduction of C4 to C16 enoyl-CoAs, though the activities toward shorter chain substrates (C4 and C6) were very low. Thiolase was also partially purified from the same source. These two enzymes were used, together with 3-hydroxyacyl-CoA dehydrogenase and the two forms of enoyl-CoA hydratase (hydratases I and II) previously purified from the same source, to reconstitute fatty acid elongation activity. The products formed from [1-14C]acetyl-CoA and decanoyl-CoA in this reconstituted system were analyzed by thin-layer chromatography and radio-gas-liquid chromatography. The system containing hydratase II produced laurate and 3-hydroxylaurate (in the form of their CoA esters) and the ratio of laurate to 3-hydroxylaurate increased as the incubation time was increased. The system containing hydratase I produced only 3-hydroxylaurate. 3-Hydroxylaurate was also the only product when enoyl-CoA reductase was omitted from the system containing hydratase II. It is concluded that hydratase II, but not hydratase I, is functional in fatty acid elongation by M. smegmatis and that enoyl-CoA reductase is also essential for the reaction. CoA and NAD+ inhibited the reconstituted elongation activity in competition with acetyl-CoA and NADH, respectively.View full abstractDownload PDF (525K) -
Shuichi FURUTA, Shoko MIYAZAWA, Takashi OSUMI, Takashi HASHIMOTO, Nobu ...1980 Volume 88 Issue 4 Pages 1059-1070
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMitochondrial and peroxisomal enoyl-CoA hydratases were purified from rat liver. The mitochondrial enzyme, with a molecular weight of 161, 000, was composed of 6 identical subunits. The molecular structure of the rat liver enzyme was very similar to that of the bovine liver enzyme. Acetoacetyl-CoA was a competitive inhibitor of the mitochondrial enzymes. The results of titration of the rat liver enzyme with acetoacetyl-CoA suggest that 3 subunits of the enzyme exhibit catalytic activity. The catalytic properties of the enzyme were studied.
The peroxisomal enzyme was composed of one polypeptide with a molecular weight of 70, 000-81, 000. Some of the enzyme molecules were shown to be cleaved to two polypeptides in the cell by the following methods: amino acid analysis, peptide mapping and immunoprecipitin reaction. The catalytic properties of the peroxisomal enzyme were different from those of the mitochondrial enzyme. The peroxisomal enzyme is a bifunctional enzyme exhibiting 3-hydroxyacyl-CoA dehydrogenase activity. Studies on the titration with acetoacetyl-CoA, the effects of salts, SH titration and proteolytic inactivation suggest that the active centers for these two reactions are located at different sites.View full abstractDownload PDF (2075K) -
Intracellular Incorporation, DNA Breakdown and CytotoxicityJiro TAKESHITA, Hiroshi MAEDA, Katsuro KOIKE1980 Volume 88 Issue 4 Pages 1071-1080
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe subcellular site of action of a proteinaceous antitumor antibiotic neocarzinostatin (NCS) was studied using normal human lymphocytes, Epstein-Barr virus transformed lymphoblastoid cells, osmotically burst lymphoblastoid cells, and colicin E1 plasmid DNA. The rate of DNA strand break in these different types of DNA was found to be in the following order: Colicin DNA>burst cell DNA>lymphoblastoid cell DNA>normal lymphocyte DNA. Furthermore, fluorescence microscopy revealed that lymphoblastoid cells incorporated more fluorescein isothiocyanate labeled NCS than normal cells. High uptake of NCS in lymphoblastoid cells coincided with a high killing rate; low uptake of NCS in lymphocytes resulted in very little cell killing. Uptake velocity using fluorescein diacetate (FDA) also showed that the lymphoblastoid cells exhibited a higher uptake of FDA coinciding with a higher killing rate.
The cell killing activity of NCS appears to be closely associated with the rate of intracellular uptake of NCS and subsequent direct degradation of DNA by the drug. This notion is reinforced by the reported finding that the dose required for DNA strand scission is only about 1/100 of that for the inhibition of cap formation. Thus DNA strand scission, rather than the cell membrane, appears to be the primary target of NCS. Enhanced incorporation of many substances is commonly observed upon transformation of cells by viruses, and our present results may provide an important clue toward the explanation of the selective toxicity toward tumor cells of NCS.View full abstractDownload PDF (1205K) -
Michiki KASAI1980 Volume 88 Issue 4 Pages 1081-1085
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe inulin exclusion volume of sarcoplasmic reticulum vesicles was studied using the ultracentrifugation method, after equilibrium penetration of solutes had been established under various solvent conditions. The intravesicular volume in equilibrium decreases with increasing salt concentration, while it does not change with neutral molecules. The concentrations of salt ions which caused the intravesicular volume to decrease to a half of the maximal volume were as follows; about 200 mm for KCI and NaCI, about 30 mm for CaC12 and MgCl2. The mechanism of the volume change can be explained in terms of the Donnan pressure model on the basis of the existence of fixed charges inside the vesicles.View full abstractDownload PDF (376K) -
Takayoshi IIO, Hiroshi KONDO1980 Volume 88 Issue 4 Pages 1087-1092
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSStatic fluorescence titration and fluorescence stopped-flow kinetic experiments on N-(7-dimethylamino-4-methyl-3-coumarinyl)-maleimide-labeled troponin C showed that the molecular kinetic mechanism of the local conformational change induced by the rapid Ca2+ binding and removal reactions with the high affinity Ca2+-binding sites (sites III and IV) can be explained by the following scheme:
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Numerical constants in this scheme were determined in this work.View full abstractDownload PDF (429K) -
Isamu MATSUMOTO, Akiko JINBO, Haruko KITAGAKI, Anne M. GOLOVTCHENKO-MA ...1980 Volume 88 Issue 4 Pages 1093-1096
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIt was found that the addition of specific sugars to solutions of several lectins induced ultraviolet difference spectra. The difference spectra of lectins from Lens culinaris, Sophora japonica, Solanum tuberosum and wheat germ have two peaks at 292 nm and 284-287 nm which are characteristic of the tryptophanyl residue. The difference spectrum of Arachis hypogaea agglutinin has two peaks at 285 nm and 279 nm which seem to be characteristic of the tyrosyl residue. In addition to the identification of these amino acid residues as being in or near the sugar binding sites of the lectins, the binding constants of these lectins with the specific sugars can be easily determined from the intensities of the difference spectra at various concentrations of sugars. This method may be useful for the simple and direct determination of the binding constants of lectins with various naturally occurring sugars which have no chromogenic groups.View full abstractDownload PDF (265K) -
Hybridization of Light and Heavy Subunits and Some Properties of an Isolated Hybrid EnzymeTakashi MATSUMOTO, Shigeki SHIRAI, Yasuyuki ISHII, Jiro TOBARI1980 Volume 88 Issue 4 Pages 1097-1102
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSHybridization reactions were carried out in vitro between the light and heavy subunits of two methylamine dehydrogenases obtained from Methylomonas J (formerly Pseudomonas sp. J) and Pseudomonas AM1. Enzymatic activity was restored with a combination of LJ (MW: 13, 000) and HA (MW: 40, 000) but not with LA (MW: 13, 000) and HJ (MW: 40, 000). This active hybrid enzyme was isolated with a Sephadex G-150 column after incubation of L, and HA. Its molecular weight was nearly identical to that of the two native enzymes (MW: 105, 000). The electrophoretic pattern of proteins cross-linked by dimethyl suberimidate showed the formation of a tetrameric structure. Its absorption spectrum was similar to that of the native enzymes. The specific activity was 4.3 and the substrate specificity resembled that of the Methylomonas J enzyme rather than that of the Pseudomonas AM1 enzyme. Michaelis constants were 290 μM for methylamine and 14 μM for phenazine methosulfate. The circular dichroism spectrum and thermal stability resembled those of the Pseudomonas AM1 enzyme. No appreciable amount of an inactive hybrid enzyme was formed in the reaction between LA and HJ, there being neither restoration of the enzymatic activity, nor formation of cross-linked tetrameric proteins with dimethyl suberimidate. Hybridization of LJ and HA was further confirmed by the appearance of three enzymatic active bands on a gel after electrophoresis of an incubation mixture of LJ, HJ, and HA. The results are consistent with a previous observation; the two methylamine dehydrogenases from either obligate or facultative methylotrophs are the α2β2-type and homologous enzymes. It is also suggested that substrate specificity and catalytic activity are directed by the light subunit, and binding affinity of the substrate to the active site, electrophoretic mobility, and thermal stability of the enzyme are endowed by the heavy subunit.View full abstractDownload PDF (1549K) -
Akihiro KUSUMI, Toshiyuki SAKAKI, Tôru YOSHIZAWA, Shun-ichi OHNI ...1980 Volume 88 Issue 4 Pages 1103-1111
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSProtein rotational mobility was measured by saturation transfer ESR of a covalently attached spin label, and lipid alkyl chain flexibility by conventional ESR of 5-doxyl and 16-doxyl stearate in rhodopsin-dimyristoylphosphatidylcholine recombinants as a function of temperature and of the protein content. Rhodopsin caused some reduction of the lipid alkyl chain flexibility, the degree of which gradually increased with the protein content. In the proteinrich recombinants, a strongly immobilized component appeared and its relative intensity increased with the protein content and at temperatures lower than that of the phospholipid phase transition. This component was ascribed to lipid spin labels entrapped in the protein clusters.
The rotational mobility of rhodopsin changed discontinuously at the host lipid phase transition. However, the change in the rotational correlation time was not large. The weakened response to the phase transition was ascribed to residual mobility in the solid phase and remaining aggregation of rhodopsin above the phase transition. The temperature dependence became more and more broadened with the increase of protein content, probably due to greater aggregation in the fluid phase and partly due to increased average viscosity. Rhodopsin-dielaidoylphosphatidylcholine recombinants were also studied for comparison and some differences in the lipid-protein interaction were noted.View full abstractDownload PDF (696K) -
Akihiro FUNAKOSHI, Yoriaki TSUBOTA, Kiyotaka FUJII, Hiroshi IBAYASHI, ...1980 Volume 88 Issue 4 Pages 1113-1118
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA simple purification method for pancreatic deoxyribonuclease I (DNase I) [EC 3. 1. 4. 3] was developed by utilizing the technique of isoelectric focusing. The active protein was resolved into at least four forms with different isoelectric points; the major components a, b, and c had isoelectric points at pH 5.2, 4.9, and 4.8, respectively, and that of the minor component d was at 4.7. The four components (a, b, c, and d) exhibited peaks similar to those observed by Salnikow et a.l after phosphocellulose chromatography (A, B, C, and D).
The four components were all free from RNase and protease activities and were very stable at 0-2°C for at least four weeks. Further, each of the four peaks exhibited a single protein band after polyacrylamide electrophoresis.
DNase I-a antibody was prepared; it was very specific for DNase I and precipitated with the other components (b, c, and d).
The mode of endonucleolytic action of pancreatic DNase I-a purified from Worthington DP grade DNase I was investigated. The sedimentation patterns in neutral sucrose gradients of digest of circular duplex DNA in an early stage of hydrolysis suggested that DNase I produces single strand scissions in the initial attack in the presence of divalent metal ions.View full abstractDownload PDF (1523K) -
Shinsei GASA, Akira MAKITA1980 Volume 88 Issue 4 Pages 1119-1128
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSGangliosides were isolated from equine kidney and spleen, and their carbohydrate and lipid moieties were characterized.
Among the long-chain bases, considerable proportions of trihydroxy bases (42.3 to 61.2% of the total bases), in which phytosphingosine was predominant, were found in all the ganglioside classes. The other major base was sphingosine. Among the constituent fatty acids, long-chain acids (with a carbon number of more than 20), comprised approximately half the total acids, with some α-hydroxy and mono-unsaturated acids.
By means of sequential hydrolysis with glycosidases coupled with methylation analysis, the following kidney and spleen gangliosides were characterized: hematoside containing both N-acetyl and N-glycolylneuraminic acids; ganglioside GM2 having both types of sialic acid; ganglioside GM, having mainly N-glycolylneuraminic acid (83 to 86%); ganglioside GD1a having mainly N-glycolylneuraminic acid (71 to 95%). Ganglioside GD3 containing almost exclusively N-glycolylneuraminic acid (93%) was found in the kidney, and ganglioside GD1b having both types of sialic acid in the spleen.View full abstractDownload PDF (637K) -
Ryuken KII, Akira SANO, Kazuyoshi YONEZAWA, Kuniyasu SAKAI, Hikaru TAB ...1980 Volume 88 Issue 4 Pages 1129-1134
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAlthough muscle glycogen phosphorylase kinase reacts preferentially with an inactive form of phosphorylase, the enzyme is able to phosphorylate in vitro multiple species of unidentified endogenous proteins in mammalian tissues such as liver. The reactions absolutely require Ca2+. Phosphate acceptor proteins are most abundant in the soluble and microsomal fractions. Sodium lauryl sulfate-slab gel electrophoresis analysis has revealed that the spectrum of phosphate acceptor proteins entirely differs from that for cyclic AMP-dependent protein kinase, although the biological significance of these reactions is unclear. Nevertheless, it is suggested that the enzyme is potentially multifunctional and plays roles in controlling some of the Ca2+-dependent processes. In contrast, myosin light chain kinase which is another species of calmodulin-dependent protein kinase seems to be strictly specific for this particular protein, and does not utilize any other endogenous protein so far tested.View full abstractDownload PDF (744K) -
III. The Kinetic Analysis of C-Nitrosoreductase Reaction Catalyzed by the Cytoplasmic Enzyme from Porcine LiverYasuyuki OGURA, Shigeo HORIE1980 Volume 88 Issue 4 Pages 1135-1139
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe reaction kinetics of the major cytoplasmic NADH-nitrosoreductase, which is the identical enzyme to alcohol dehydrogenase [EC 1. 1. 1. 1], was studied with a partially purified preparation from porcine liver.
On the basis of the data obtained, the following scheme is proposed as the mechanism of this enzyme reaction:
E+SK1_??_ES E+nK2_??_EN ES+NK2_??_ESN
EN+SK1_??_ESN ESNK1_??_E'+P1 E'+NK2_??_E+p1+p2,
where E and E' are the enzyme unit (one subunit of alcohol dehydrogenase) and an intermediate form of the enzyme unit-substrate compound which appears by two-electron reduction of the enzyme unit-substrate compound, respectively, S is p-nitrosophenol (p-NSP), N is NADH, and P1 and P2 are NAD+ and p-aminophenol (p-AmP), respectively. In this case, it is assumed that k1_??_k2.
Para-aminophenol, the reaction product, showed an inhibition competitive to p-NSP at fixed concentrations of NADH and also showed a mixed-type inhibition to NADH at fixed concentrations of p-NSP. NAD+ inhibited the reaction in a competitive manner to NADH at fixed concentrations of p-NSP and in a non-competitive manner to p-NSP at fixed concentrations of NADH. These results can also be accounted for by the proposed mechanism.View full abstractDownload PDF (346K) -
IV. Partial Purification and Kinetic Properties of Porcine Heart C-NitrosoreductaseShigeo HORIE, Yasuyuki OGURA1980 Volume 88 Issue 4 Pages 1141-1150
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn NAD (P) H-dependent C-nitrosoreductase was purified 90 fold from porcine heart cytosol fraction by ammonium sulfate fractionation, gel filtration with Sephadex G-100, ion-exchange chromatography on DEAE-Sephadex A-50, and affinity chromatography on 5'-AMP-Sepharose. The enzyme had no aldehyde reductase activity and showed a pH optimum of 5.5. Its molecular weight estimated by gel filtration was about 65, 000 to 70, 000 daltons. In the reaction catalyzed by this enzyme, 2 mol of NADH were consumed per mol p-nitro-sophenol (p-NSP) reduced to p-aminophenol (p-AmP). Nitrosobenzene and other aryl nitroso compounds were also reduced but neither phenylhydroxylamine nor hydroxylamine could serve as the electron acceptor.
Kinetic measurements were also carried out and, based on the data obtained, the following scheme is proposed for the mechanism of the reaction:
E+N_??_EN EN_??_E'+P1 E'+N_??_E'N
E'N_??_E''+P1 E''+S_??_E''S E''S_??_E+P2,
where E, E', and E'' represent the active enzyme unit, the enzyme unit after two-electron reduction, and the enzyme unit after four-electron reduction, respectively, N is NADH, S is p-NSP, and P1 and P2 are NAD+ and p-AmP, respectively.
Para-aminophenol showed an inhibition noncompetitive with NADH and also one apparently noncompetitive with p-NSP. NAD+ showed an inhibition competitive with NADH and one uncompetitive with p-NSP. These results can also be accounted for by the proposed mechanism.View full abstractDownload PDF (704K) -
Makoto KAWAKAMI, Panagiotis A. TSONIS, Koji NISHIO, Shosuke TAKEMURA1980 Volume 88 Issue 4 Pages 1151-1157
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTwo species of glycine tRNA (tRNA1Gly and tRNA2Gly) were purified from the posterior silk glands of Bombyx mori. Digestion of tRNA1Gly with RNase T1 revealed that this tRNA corresponds to the species which has recently been sequenced by Garel and Keith (1), and Zu_??_iga and Steitz (2), independently. However, the position 9 of our tRNA1Gly was occupied by unmodified guanosine instead of m1G. The codon recognition properties of highly puri-fied tRNA1Gly and tRNA2Gly were investigated in detail according to the method of Nirenberg and Leder (3). All four glycine codons were recognized by tRNA1Gly and by tRNA2Gly. These results suggest the presence of abnormal base-pairs between the first base G of the anticodon and all the third bases of the codons, or the recognition by “two-out-of-three” type reading.View full abstractDownload PDF (441K) -
II. The Ability of Guinea Pig Alveolar Macrophages to Produce H2O2Mizuho KANEDA, Katsuko KAKINUMA, Teruhide YAMAGUCHI, Kokichi SHIMADA1980 Volume 88 Issue 4 Pages 1159-1165
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSGuinea pig alveolar macrophages (A-M∅) were studied with respect to the phagocytic metabolism: the respiratory burst and its KCN sensitivity, the ability to generate H2O2, and myeloperoxidase (MPO) activity. Only fifty percent of the O2 uptake by A-M∅ samples during phagocytosis was inhibited by the addition of 1mM KCN. Guinea pig A-M∅ released H2O2 amounting to 7.7 and 12.5 nmol/min/107 cells upon addition of E. coli in the absence and presence of anti-E. coli antibody, respectively. Myristic acid, an effective membrane activator, induced a marked release of H2O2 amounting to 16.1 nmol/min/107 cells. We observed a high MPO activity in some alveolar lavage cells which contained a large number of polymorphonuclear leukocytes (PMN), but none at all in preparations containing fewer PMN. The MPO activity detected did not seem to be due to A-M∅, but to the PMN contained in the preparations.View full abstractDownload PDF (509K) -
Teruhiro TAKABE, Satsuki NIWA, Hiroshi ISHIKAWA, Kiyoshi TAKENAKA1980 Volume 88 Issue 4 Pages 1167-1176
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe electron transfer reactions of membrane-bound monomeric cytochrome ƒ from Brassica komatsuna (Brassica rapa L. var. perviridis Bailey) with hexacyanoferrate (II)-(III) have been studied as a function of pH, ionic strength and temperature. The second-order rate constant for the oxidation of cytochrome ƒ by Fe(CN)63- at pH 7.0, μ 0.1M, and 20°C is 1.7×105, M-1•S-1, which is similar to the value of oligomeric cytochrome ƒ from parsley. The activation parameters obtained were ΔH_??_=-0.87 kcal/mol and ΔS_??_-=38 cal/mol•deg. Respective rate constant and activation parameters obtained for the reduction of cytochrome ƒ by Fe(CN)64- were k=1.7×104 M-1•S-1, ΔH_??_=+6.7 kcal/mol, and ΔS_??_=-16 cal/mol.deg. Both the rate constants for the oxidation and the reduction of cytochrome ƒ markedly decreased with increasing ionic strength. The results indicate that the oxidation and the reduction take place at a positively charged site on the cytochrome ƒ surface, and electrostatic interactions are important for these reactions. The participation of protons and specific amino acid residues in electron transfer reactions of cytochrome ƒ is implied from the pH results. Alkaline isomerization of ferricytochrome ƒ was not observed. The midpoint potential of cytochrome ƒ has a constant value of 360 mV between pH 5.0-8.9, and decreases by about 55 mV per pH unit above 8.9. The results are compared with the data for horse heart cytochrome c and Euglena gracilis cytochrome c-552. These data are discussed in relation to the theories of electrostatic corrected outer-sphere electron transfer of Marcus and multiphonon nonadiabatic electron tunneling of Jortner and Hopfield.View full abstractDownload PDF (681K) -
Satsuki NIWA, Hiroshi ISHIKAWA, Sueki NIKAI, Teruhiro TAKABE1980 Volume 88 Issue 4 Pages 1177-1183
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe protein-protein electron transfer reactions between cytochrome ƒ and plastocyanin, both purified from Brassica komatsuna (Brassica rapa L. var. perviridis Bailey), have been studied as a function of pH, ionic strength, and temperature. The second-order rate constant for the oxidation of ferrocytochrome ƒ by plastocyanin was found to be k=4.5×107 M-1•s-1 at pH 7.0, μ 0.2M, and 20°C, with activation parameters ΔH_??_=8.4 kcal/mol and ΔS_??_=4.9 cal/mol•deg. Respective rate constant and activation parameters obtained for the reduction of ferricytochrome ƒ by plastocyanin were k=1.9×107M-1•s-1, ΔH_??_=8.6 kcal/mol, and ΔS_??_=3.9 cal/mol•deg. The high rate constants for these reactions are attributable not to a low activation enthalpy but to a positive activation entropy term. The rate constants both for the oxidation and the reduction of cytochrome f by plastocyanin drastically decreased with increasing ionic strength, indicating the importance of electrostatic interactions. Divalent cations are more effective than monovalent cations in reducing the rates of these reactions. The rate constants for the oxidation of cytochrome ƒ by plastocyanin are constant between pH 6.0 and 9.0 but decrease markedly above pH 9.0 and below pH 6.0. In the case of the reduction of cytochrome ƒ by plastocyanin, an optimum pH around 7.0 was obtained and a biphasic feature was observed at alkaline pH. The results are discussed in relation to photosynthetic electron transport systems.View full abstractDownload PDF (509K) -
Hiroshi MAEDA1980 Volume 88 Issue 4 Pages 1185-1191
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA new sensitive, rapid and simple method for lysozyme assay is described which is based on either fluorescence polarization or fluorescence intensity using fluorescein-labeled peptidoglycan as a substrate. The peptidoglycan was obtained from Micrococcus lysodeikticus after extensive digestion with Pronase and washing with Triton X-100 followed by various solvents. Subsequently, it was labeled with fluorescein isothiocyanate (FITC) at the amino group of the peptide. When the FITC-labeled substrate was subjected to lysozyme digestion, an increase of fluorescence intensity or a decrease of fluorescence polarization value (P value) was apparent in five minutes at a lysozyme concentration as low as 0.1 or 0.01 μg/ml, respectively. The effect of other hydrolytic enzymes including -mannosidase, proteases and RNase on the P value was found to be negligible. The measured values represented the specificity and dose of lysozyme added. Apparent Vmax and Km values for two different lysozymes, chicken egg white and human, could be determined by this method.View full abstractDownload PDF (520K) -
Kiyoshi HAYASAKA, Hideo KOCHI, Koichi HIRAGA, Goro KIKUCHI1980 Volume 88 Issue 4 Pages 1193-1199
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSGlycine decarboxylase, tentatively called P-protein as a constituent of the glycine cleavage system, was purified to near homogeneity from rat liver mitochondria. The purified P-protein was a homodimer with a molecular weight of about 210, 000, consisting of identical subunits with a molecular weight of 105, 000. In the exchange reaction of the carboxyl carbon of glycine with CO2 catalyzed by the purified P-protein in the presence of H-protein, the pH optimum was 6.7, Km for glycine was 6.6mM, and Km for H-protein was 7.4 μm. A specific rabbit antibody against the purified rat liver P-protein was prepared. Ouchterlony double diffusion analysis and immunoinhibition experiments using this antibody revealed immuno-logical cross-reactivity among the P-proteins from various species of animals such as carp, frog, snake, chicken, bovine, and human, suggesting a quite conservative evolution of the glycine cleavage system.View full abstractDownload PDF (1197K) -
Tetsuro MOHRI, Fumiko MIYANAGA, Naomi SAKURAI, Tsuneo TAKADERA, Takao ...1980 Volume 88 Issue 4 Pages 1201-1206
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIntensity of fluorescence induced by reaction of a SH-directed fluorogenic reagent with whole Chang liver cells or their plasma membrane preparations which were previously treated with 0.5mM N-ethylmaleimide (NEM) plus 5mM leucine was enhanced by 30% or more in the presence of 5mM leucine or valine in assay medium consisting of Tris-Hepes buffer, pH 6.85, compared with the control. The dissociation constant for binding of leucine to the membrane protein (s) was estimated to be approximately 3mM from the increments of fluorescence intensity with increasing leucine concentration. On the other hand, the amount of [14C]NEM bound to the membrane preparations pretreated with NEM plus leucine was significantly reduced in the presence of leucine in the reaction medium. A decrease of reactivity of SH groups near the binding sites of the membrane proteins and of mobility of the fluorescent adducts on binding leucine was suggested to explain all these results consistently.View full abstractDownload PDF (416K) -
Shinnichiro SUZUKI, Wasuke MORI, Jun KINO, Yasuo NAKAO, Akitsugu NAKAH ...1980 Volume 88 Issue 4 Pages 1207-1209
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe cobalt(II)-substituted hemocyanin was first prepared by dialysis of apohemocyanin against Tris-HC1 buffer (pH 8.0) containing cobalt(II) ion. The amount of cobalt(II) introduced into apohemocyanin reached 47% of the total sites for copper ion in native hemocyanin, being estimated as nearly complete formation of the half-filled cobalt(II)-hemocyanin (Co(II)-Hc). The Co(II)-Hc did not bind oxygen molecule even under O2-atmosphere. The spectral data indicated that the Co(II) is in tetrahedral geometry (high-spin state).View full abstractDownload PDF (180K) -
Mamoru TAMURA, Ryuichiro ARAKI, Toshihisa ISHIKAWA, Katsuhiro SAGISAKA ...1980 Volume 88 Issue 4 Pages 1211-1213
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIt was demonstrated spectrophotometrically that in the hemoglobin-free perfused rat heart met- and ferrylmyoglobins formed upon infusion of sodium nitrite, and ethyl hydroperoxide were reduced to form oxymyoglobin with a half time of about 3 and 4 min, respectively. The rate of metmyoglobin reduction was about 30 nmol/min/g wet weight in the rat heart.View full abstractDownload PDF (232K) -
Mitsuyo OKAZAKI, Ichiro HARA1980 Volume 88 Issue 4 Pages 1215-1218
Published: October 01, 1980
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSWe succeeded in the separation of human serum high density lipoprotein into their subfractions (HDL2 and HDL3) by high performance liquid chromatography with gel permeation columns (1, 2). The cholesterol contents in HDL2 and HDL3 for normal men and women (n=42) and for the patients with atherosclerotic heart disease (n=20) were measured by this separation method. The results in our experiment agree closely with those reported by other investigators using the ultracentrifugal method.View full abstractDownload PDF (215K)
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