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Volume 80 (1976)
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- Issue 5 Pages 903-
- Issue 4 Pages 653-
- Issue 3 Pages 417-
- Issue 2 Pages 195-
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Volume 80, Issue 5
Displaying 1-32 of 32 articles from this issue
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Seitaro MUTOH, Ikuo FUNAKOSHI, Ikuo YAMASHINA1976 Volume 80 Issue 5 Pages 903-912
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSPlasma membranes were isolated from an ascites hepatoma, AH 130 FN, a free-cell type subline of AH 130, by the fluorescein mercuric acetate (FMA) method. Glyco-peptides and mucopolysaccharides were prepared from the membranes by pronase digestion then fractionated chromatographically and electrophoretically. Isolated fractions were analyzed for amino acid and carbohydrate compositions. The results were compared with those for corresponding fractions from AH 66 and AH 130 ((1974) J. Biochem. 76, 319-333; (1975) J. Biochem. 78, 863-872).
The fraction excluded from Sephadex G-50 contained mucopolysaccharides and a series of glycopeptides. The mucopolysaccharides were identified as chondroitin sulfate A on the basis of their chemical composition, electrophoretic behavior on cellulose acetate and digestibility with chondroitinase AC [EC 4. 2. 2. 5]. This contrasts with previous findings that mucopolysaccharides from the corresponding fractions from AH 130 and AH 66 were heparan sulfate.
The chemical composition of the glycopeptides, which showed high contents of threonine, serine, galactose, galactosamine, glucosamine, and sialic acid, indicated the presence of glycopeptides with O-glycosidic linkages. The glycopeptides also contained a small but significant amount of aspartic acid, suggesting that N-glycosidic glycopeptides were also contained in this fraction.
The fraction included in Sepnadex G-50 contained N-glycosidic glycopeptides as major components, since the carbohydrate moieties were composed of fucose, galactose, mannose, glucosamine, sialic acid, and a smaller amount of galactosamine. The presence of galactosamine suggested that 0-glycosidic glycopeptides were present as minor components. Glycopeptides with both O- and N-glycosidic linkages were isolated from AH 130, but not from AH 66.View full abstractDownload PDF (1334K) -
IV. Purification and Properties of a Less-Random Type CellulaseGentaro OKADA1976 Volume 80 Issue 5 Pages 913-922
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA cellulase [EC 3. 2. 1. 4] component was purified from a crude cellulase preparation of Trichoderma viride (Meicelase) by consecutive column chromatography procedures, and was designated as cellulase III. The enzyme was homogeneous on polyacrylamide gel disc electrophoresis. The molecular weight of the enzyme was estimated to be about 45, 000 by gel filtration.
The optimum pH and temperature of the enzyme were pH 4.5-5.0 and 50°, respectively. The enzyme was stable over the range of pH 4.5-7.5 at 4° for 24 hr, and retained 40% of the original carboxymethylcelIulose-saccharifying activity after heating at 100° for 10 min. The enzyme was completely inactivated by 1 mM Hg2+ and partially by 1mM Ag+ and Cu2+.
The enzyme was characterized as a less-random type cellulase on the basis of its action on carboxymethylcellulose. The enzyme split cellohexaose, retaining the β-configuration of the anomeric carbon atoms in the hydrolysis products. The Km values of cellulase III for cellooligosaccharides decreased in parallel with increase of the chain length of the substrates, while Vmax values showed a tendency to increase. The enzyme produced predominantly cellobiose and glucose from various cellulosic substrates as well as from higher cellooligosaccharides. Cellulase III preferentially attacked the aglycone linkage of p-nitrophenyl β-D-cellobioside. The enzyme was found to catalyze the rapid synthesis of cellotetraose from cellobiose (condensation action).View full abstractDownload PDF (791K) -
Hiroko NAKAGAWA, Yoshiko KASHIWABARA, Genji MATSUKI1976 Volume 80 Issue 5 Pages 923-928
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSMycobacterium smegmatis cells incorporated [1-14C] oleic acid into triacyiglycerols (TG) from the medium more rapidly than shorter chain fatty acids, caprilic and butyric acids. This incorporation was inhibited more strongly by 10-3 M N-ethylmaleimide than by 10-8 M KCN.
[14C] TG in the bacterial cells was utilized when the cells were in poor nutritional conditions, such as phosphate buffer (pH 7.0) containing oleic acid.
Accumulation of TG was observed in the cells at late stages of growth.
Diglyceride acyltransferase [EC 2. 3. 1. 20] activity was detected in a cell-free extract from this bacterium. The pH optimum of this enzyme was between pH 7 and 9. F- and Tween 20 showed remarkable enhancing and inhibitory effects, respectively.View full abstractDownload PDF (402K) -
Yasushi SAITO, Nobuo MATSUOKA, Hiromichi OKUDA, Setsuro FUJII1976 Volume 80 Issue 5 Pages 929-934
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSLipase [EC 3. 1. 1. 3] depleted lipid micelles, in which lipolysis was not elicited by adrenaline, were prepared from lipid micelles. When these lipase-depleted lipid micelles incubated with adipose tissue extract containing lipase activity, adrenaline-induced lipolysis was restored to almost the same level as that of native lipid micelles. Adrenaline-induced lipolysis was not restored when the lipase-depleted lipid micelles were homogenized or sonicated. Various tissue extracts from kidney, lung, liver, and pancreas, and post-heparin plasma, which contained lipase activity, restored adrenaline-induced lipolysis in lipase-depleted lipid micelles.View full abstractDownload PDF (417K) -
Osamu ITASAKA, Mutsumi SUGITA, Haruhiko YOSHIZAKI, Taro HORI1976 Volume 80 Issue 5 Pages 935-936
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe anomeric configurations of Corbicula ceramide dihexoside and ceramide trihexoside were determined by chromium trioxide oxidation and the structures of these lipids were shown to be Man-β(1→4)-Glc-β(1→1)-ceramide and Man-α(l→4)-Man-β(1→4)-Glc-β(1→1)-ceramide. These results are compatible with those obtained by enzymic hydrolysis reported previously.View full abstractDownload PDF (163K) -
I. Purification and Complete Digestion with Ribonuclease T1 and Pancreatic Ribonuclease AOsamu KOIWAI, Masazumi MIYAZAKI1976 Volume 80 Issue 5 Pages 937-950
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe methionine acceptor activity of a crude tRNA from bakers' yeast was resolved into two peaks (I and II) by column chromatography on DEAE-Sephadex A-25 with a 1 M phosphate system. Methionine tRNA from peak II was not formylated by E. coli methionyl-tRNA transformylase [EC 2. 1. 2. 9] after being charged with methionine, whereas that from peak I was formylatable under the same conditions. A substantial amount of unlabelled methionine tRNA, tRNAMetm, was highly purified from the peak II fraction by successive chromatographic procedures. The purified tRNAmet was digested with pancreatic ribonuclease A [EC 3. 1. 4. 22] and ribonuclease T1 [EC 3. 1. 4. 8]. The digestion products were isolated into individual components and completely sequenced. The results of sequence analysis of the two RNase digests were in good agreement and indicated that the chain length of this tRNA is 76, including 13 modified nucleotides. These oligonucleotide fragments can be constructed into a unique total sequence, assuming a few conventional features of clover leaf structure for the tRNA, as in the cases of other tRNA's so far sequenced. The complete sequence of this tRNA was established by analyses of partial digestion products with RNase T1, as reported in the accompanying paper.View full abstractDownload PDF (999K) -
II. Partial Digestion with Ribonuclease T1 and Derivation of the Complete SequenceOsamu KOIWAI, Masazumi MIYAZAKI1976 Volume 80 Issue 5 Pages 951-959
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSLarge oligonucleotides obtained from partial RNase Tt digestion of tRNAMetm from bakers' yeast (S. cerevisiae, strain Y 185) were isolated by chromatographic procedures and sequenced. The complete sequence of the tRNAMetm was established from the results of this partial digestion, together with those of the complete RNase Tt and A [EC 3. 1. 4. 8 and 22] digestions of tRNAmet reported in the preceding paper. The structure of this tRNAMetm was arranged into a clover leaf comparable with those of other tRNAmet species including bakers' yeast initiator tRNA.View full abstractDownload PDF (581K) -
Nobuo SHIMAMOTO1976 Volume 80 Issue 5 Pages 961-968
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA general kinetic method was developed to analyze enzyme-catalyzed systems compli-cated by the presence of activation or inhibition by substrate. The method was applied to the a-chymotrypsin [EC 3. 4. 21. 1]-catalyzed hydrolysis of p-chlorophenyl and p-methoxyphenyl acetates. Deacylation rate constants which were not complicated by substrate activation were obtained. The analysis shows that the abnormal sub-stituent dependence of kcat in the steady state hydrolysis is due not to substrate activation but to inappropriateness of the two-step mechanism or the existence of more than one acetyl-enzyme intermediate.View full abstractDownload PDF (615K) -
Hiroko TAKESADA, Mamoru NAKANISHI, Masamichi TSUBOI, Katsumi AJISAKA1976 Volume 80 Issue 5 Pages 969-974
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe proton magnetic resonance spectrum of bovine α-lactalbumin has been observed, and three peaks assignable to the position-2 CH protons of the three histidine residues (His 32, 68, and 107) of this protein have been subjected to detailed examination. The assignments of these peaks to His 32, 68, and 107 were made on the basis of the difference in their reactivities with iodoacetic acid. The rate constants of the hydrogen-deuterium exchange reactions were found to be 8.0×10-5, 2.6×10-4, and 8.0×10-5 min-1, respectively, at pH 8.5 and at 35°, while at 62° all three were found to be 0.84_??_1.1×10-2 min-1. On the basis of these data, it has been shown that, in the native form of this protein, His 68 is the most exposed to the solvent while His 32 and His 107 are buried slightly deeper in the surface of the molecule. The fluctuation amplitudes γ, or the effective chances of His 32, 68, and 107 to be fully exposed to the solvent, were found to be 0.4, 1.3, and 0.4, respectively.View full abstractDownload PDF (439K) -
VI. Effects of Acid Protease-Specific Inhibitors on the Acid Proteases from Aspergillus niger var. macrosporusWen-Jong CHANG, Satoshi HORIUCHI, Kenji TAKAHASHI, Makoto YAMASAKI, Yu ...1976 Volume 80 Issue 5 Pages 975-981
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. The Type B acid protease from Aspergillus niger var. macrosporus was inactivated by reaction with diazoacetyl-DL-norleucine methyl ester (DAN), DL-1-diazo-3-tosylamido-2-heptanone (DTH), and L-1-diazo-3-tosylamido-4-phenyl-2-butanone (DTPB) in the presence of cupric ions. The reaction with DAN took place with 1:1 stoichiometry. The enzyme was also inactivated by reaction with 1, 2-epoxy-3-(p-nitrophenoxy)-propane (EPNP) with concomitant incorporation of approximately two EPNP molecules per molecule of protein. Moreover, these reactions of DAN and of EPNP were markedly inhibited by pepstatin. These results seem to indicate that, as in the case of porcine pepsin [EC 3. 4. 23. 1] and related acid proteases, the enzyme has two essential carboxyl groups at the active site, one reactive with DAN and related diazo reagents in the presence of cupric ions and the other reactive with EPNP, and that pepstatin binds in the vicinity of these residues.
2. The Type A acid protease from the same mold, on the other hand, was found to be markedly less sensitive to these specific inhibitors. Under conditions where the Type B enzyme was completely inactivated by DAN and related diazo reagents, only partial inactivation of this enzyme occurred. The effect of prior mixing of DAN and cupric ions on the pH profile of inactivation was also different from that for the Type B enzyme. Moreover, the Type A enzyme was not inactivated by EPNP. These results thus indicate that the nature of the active site of the Type A enzyme is rather different from that of the Type B enzyme and hence that the Type A enzyme belongs to a different class of acid proteases from the Type B enzyme.View full abstractDownload PDF (495K) -
Purification and CharacterizationTakashi KAGEYAMA, Kenji TAKAHASHI1976 Volume 80 Issue 5 Pages 983-992
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA new pepsinogen component, pepsinogen C, was purified from the gastric mucosa of Japanese monkey. The chromatographic behavior of this component on DE-32 cellulose was coincident with that of pepsinogen 111-2 previously reported (l), and final purification was performed by large-scale polyacrylamide disc gel electro-phoresis. The molecular weight was 35, 000 as determined by gel filtration. The ratios of glutamic acid to aspartic acid and of leucine to isoleucine were higher than those of other Japanese monkey pepsinogens. The activated form, pepsin C, had a molecular weight of 27, 000, and contained a large number of glutamic acid residues. The optimal pH for hemoglobin digestion was 3.0. Pepsin C could scarcely hydrolyze the synthetic substrate, N-acetyl-L-phenylalanyl-3, 5-diiodo-L-tyrosine (APDT). 1, 2-Epoxy-3-(p-nitrophenoxy)propane (EPNP), p-bromophenacyl bromide, and diazoacetyl-DL-norleucine methyl ester (DAN) inhibited pepsin C [EC 3. 4. 23. 3] in the same way as pepsin 111-3 of Japanese monkey, The susceptibility to pepstatin of pepsin C was lower than that of pepsin III-3, and 500 times more pepstatin was required for the same inhibitory effect. The classification and nomenclature of Japanese monkey pepsinogens and pepsins are discussed.View full abstractDownload PDF (1231K) -
Toshiharu HASE, Keishiro WADA, Morikazu OHMIYA, Hiroshi MATSUBARA1976 Volume 80 Issue 5 Pages 993-999
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe amino acid sequence of the major component of ferredoxin isolated from a blue-green alga, Nostoc muscorum, grown under N2 as the sole nitrogen source has been studied. The use of a combination of sequence analyzer, carboxypeptidases, and manual Edman degradations on tryptic and chymotryptic peptides of carboxymethyl-ferredoxin has established the amino acid sequence, which consists of 98 amino acid residues. Only four cysteine residues were present, located at positions 41, 46, 49, and 79. These residues must fulfil the minimum requirement in this ferredoxin for the chelation of two iron atoms, as postulated previously. The sequence is similar to those of Spirulina ferredoxins in having two extra residues at positions 10 and 14 compared with other chloroplast-type ferredoxins. Sequence comparison among blue-green algal ferredoxins suggests that Nostoc muscorum ferredoxin is more closely related to Spirulina ferredoxins than to Aphanothece major ferredoxin.View full abstractDownload PDF (518K) -
Shoei FURUKAWA, Kyozo HAYASHI1976 Volume 80 Issue 5 Pages 1001-1009
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSNerve growth factor was isolated from the venom of Naja naja atra by ion exchange and gel permeation chromatography and was found to be homogeneous by disc gel electrophoresis. The molecular weight was estimated to be approximately 20, 000 by gel filtration and 22, 000 by ultracentrifugation. This protein, which showed an isoelectric point of pH 7.02, probably consists of two subunits of equal molecular weight which are held together or interact with each other noncovalently. The biological activity survives treatment by a number of proteolytic enzymes, such as trypsin [EC 3. 4. 21. 4], chymotrypsin [EC 3. 4. 21. 1], and pepsin [EC 3. 4. 23. 1].View full abstractDownload PDF (658K) -
Shin NAKAMURA, Sadaaki IWANAGA, Toshie HARADA, Makoto NIWA1976 Volume 80 Issue 5 Pages 1011-1021
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA clottable protein, named coagulogen, was highly purified from the amoebocyte lysate of Japanese horseshoe crab (Tachypleus tridentatus) by a method similar to that used for the lysate of Limulus polyphemus amoebocytes. The isolated material gave, a single protein band on analytical gel electrophoresis at pH 3.2, gel electro- focusing, and sodium dodecyl sulfate (SDS) gel electrophoresis with or without 2-mercaptoethanol. It was 90 percent coagulable, and the total yield from 10ml of the amoebocyte lysate was about 40mg.
The sedimentation coefficient of purified coagulogen was 2.6 S and its molecular weight was estimated to be about 15, 300 by sedimentation equilibrium analysis, The molecular weight estimated by SDS-gel electraphoretic analysis was 19, 500±1, 000. This discrepancy was apparently due to abnormal mobility arising from the basic nature of this protein on electrophoresis. The protein had a high isoelectric point of pH 10.0±0.2, as measured by the isoelectric focusing technique. It consisted of a total of 132 to 135 amino acid residues and contained high levels of basic amino acids, which accounted for more than 16 per cent of the total amino acid residues. No methionine was detected. High contents of valine, half-cystine, glutamic acid (glutamine), and phenylalanine were found. The N-terminal sequence of the first three residues of the coagulogen was Ala-Asx-Thr, and its C-terminal residues was identified as phenylalanine, indicating that it consists of a single polypeptide chain. It is of interest that the first three N-terminal residues are homologous with those of the Aa-chain. of non-human primate fibrinogen.View full abstractDownload PDF (3419K) -
Takachika AZUMA, Kozo HAMAGUCHI1976 Volume 80 Issue 5 Pages 1023-1038
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe noncovalent interaction of light (L) chain with heavy (H) chain or Fd isolated from a human myeloma protein Jo (IgGl, k) was studied by following circular dichroic (CD) change at 235 nm. The dimerization constants of Jo-L chain determined by measuring the CD change at 293 nm with protein concentration showed that the Jo-L chain exists as the monomeric form under the experimental conditions used for recombination with H chain. The second-order rate constants for the interaction between H and L chains were in good agreement with those for the interaction between Fd and L chain at various pH values. The binding behavior of L chain to Fd could be described by a single association constant. In the interpretation of the binding of L chain to H chain, however, it was necessary to assume that the binding of L chain to one of the two sites on H chain dimer (H2) decreases the affinity of the other site for L chain. The binding constant of the first L chain to H2 was the same as that of L chain to Fd. Renaturation processes of L chain, Fd, Fab (SS) fragment (with intact interchain disulfide bond), and Fab(RA) fragment (in which the interchain disulfide bond had been reduced and alkylated) from the denatured states in 0.5 or 1 M acetic acid on neutralization were studied. The renaturation of Fd occurred very rapidly, while that of L chain consisted of a very rapid process and a slow process which followed first-order kinetics. The renaturation process of Fab(SS) consisted of rapid and slow phases, of which the latter followed first-order kinetics. The renaturation process of Fab (RA) also consisted of rapid and slow phases, but the latter process followed second-order kinetics, The overall rate constant of renaturation of Fab (RA) was the same as that of the reformation of Fab (RA) from isolated Fd and L chain. On the basis of these facts, the kinetic mechanism by which Fd and L chain recombine to yield Fab (RA) can be described in terms of the scheme Fd+L_??_Fd…L_??_Fab (RA), where Fd…L is an intermediate, and CD change is only observed in the second unimolecular process and not in the first bimolecular process.View full abstractDownload PDF (1160K) -
II. Isolation of Transfer RNA Precursors from the Posterior Silk Gland of Bombyx moriKen-ichi TSUTSUMI, Reiko MAJIMA, Kensuke SHIMURA1976 Volume 80 Issue 5 Pages 1039-1045
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe occurrence of precursors to tRNA in the post-polysomal fraction of the posterior silk gland of Bombyx mori was demonstrated by pulse-chase labeling and DNA-RNA hybridization competition experiments. These precursors had molecular sizes ranging from 4S to 5S on polyacrylamide gel electrophoresis.
Analysis of the incorporation of the methyl group from [methyl-14C] methionine revealed that a radioactive peak on polyacrylamide gel appeared in the 4, 5S region during brief labeling. This suggested that some methylation occurred at the 4.5S precursor step.View full abstractDownload PDF (523K) -
II. Further Studies by Electron Spin ResonanceKen-ichi ARAI, Toyozo MAEDA, Masao KAWAKITA, Shun-ichi OHNISHI, Yoshit ...1976 Volume 80 Issue 5 Pages 1047-1055
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe conformational transitions of polypeptide chain elongation factor Tu (EF-Tu) associated with the ligand change from GDP to GTP and also with the displacement of GDP by elongation factor Ts (EF-Ts) have been investigated using the spin-labeling technique. Of the two reactive sulfhydryl groups in EF-Tu, the one essential for interaction with aminoacyl-tRNA was selectively labeled with various kinds of iodo-acetamide or maleimide spin-labeling reagents. The electron spin resonance (ESR) spectra of EF-Tu•GDP labeled with these reagents generally consisted of two com-ponents, one narrow and one broad, corresponding to labels relatively weakly and strongly immobilized, respectively. The degree of immobilization and the ratio of the narrow to the broad components were different for each kind of label used. The spectra of spin-labeled EF-Tu•GDP changed markedly when its GDP moiety was replaced by GTP through incubation with phosphoenolpyruvate and pyruvate kinase [EC 2. 7. 1. 40], the broad component increasing at the expense of the narrow component.
The reversible nature of the conformational change was confirmed with EF-Tu labeled with a maleimide reagent. The GTP-induced spectral change was reversed upon conversion of labeled EF-Tu•GTP to EF-Tu•GDP by addition of excess GDP.
A similar type of spectral change was also observed when spin-labeled EF-Tu•GDP was incubated with EF-Ts to form labeled EF-Tu•EF-Ts complex. The extent of the spectral change induced by EF-Ts was even greater than that induced by GTP.
These results, together with those obtained by studies with hydrophobic and fluorescent probes (Arai, Arai, Kawakita, & Kaziro (1975) J. Biochem. 77, 1095-1106) indicate that a reversible conformational change is induced in EF-Tu near the sulf-hydryl group that is essential for interaction with aminoacyl-tRNA.View full abstractDownload PDF (708K) -
Naoko ARAI, Ken-ichi ARAI, Toyozo MAEDA, Shun-ichi OHNISHI, Yoshito KA ...1976 Volume 80 Issue 5 Pages 1057-1065
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe conformational transition of the polypeptide chain elongation factor G (EF-G) induced by interaction with guanine nucleotide has been investigated by means of the spin-labeling technique. Various spin-label probes were attached specifically to the sulfhydryl group of the protein that is essential for binding to ribosomes, and the effects of these ligands on the electron spin resonance (ESR) spectra were examined.
It was found that the ESR spectra of EF-G labeled with nitroxide maleimide reagents were modified by the addition of various guanine nucleotides such as GDP, GTP and, to a lesser extent, by Gpp (NH) p and Gpp (CH2) p, indicating that confor-mational changes accompany the binding of nucleotide ligand. However, the ESR spectra of labeled EF-G•GDP and EF-G•GTP were almost identical.
On the other hand, when EF-G was labeled with nitroxide iodoacetamide reagents, a clear difference in the ESR spectra of EF-G•GDP and EF-G•GTP derivatives was observed. In this case, the spectral shape of the spin-labeled EF-G in the presence of GTP or its analogs, Gpp (NH) p or Gpp (CH2) p, was quite similar to that of free, unliganded EF-G derivative.
These results, together with those previously obtained using hydrophobic probes (Arai, Arai, & Kaziro (1975) J. Biochem. 78, 243-246) demonstrate the existence of an EF-G•guanine nucleotide binary complex. They also indicate that there is a substantial difference in conformation between free EF-G, EF-G•GDP, and EF-G•GTP near the active site essential for interaction with ribosomes.View full abstractDownload PDF (628K) -
Seiei TANAKA, Saburo NAGAHAMA, Masazumi TAKESHITA, Yoshimasa YONEYAMA1976 Volume 80 Issue 5 Pages 1067-1071
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe molecular weight of protoheme ferro-lyase [EC 4.99.1.1], a mitochondrial enzyme, was estimated by the radiation inactivation method. Irradiation in vacuo caused less inactivation than that in air. The approximate molecular weight determined by this method was in the range from 250, 000 to 320, 000. The significance of the location of the enzyme in connection with its role in heme synthesis is discussed on the basis of Singer's membrane theory.View full abstractDownload PDF (354K) -
Kihachiro HORIIKE, Kiyoshi SHIGA, Akio ISOMOTO, Toshio YAMANO1976 Volume 80 Issue 5 Pages 1073-1083
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. From the standpoint of monomer-dimer equilibrium of hog kidney D-amino acid oxidase [EC 1. 4. 3. 3] and the interaction between the enzyme and small molecules, the effect of pH on the binding of p-aminobenzoate to the monomer and dimer of the enzyme was studied by kinetic methods and spectrophotometric titration.
2. The maximum binding number of p-aminobenzoate to the dimer is two molecules, and there is no interaction between the two active sites of the dimer (i.e., no coop-erativity) over the range of pH from 6.5 to 10.
3. The affinity of the dimer for p-aminobenzoate is several times higher than that of the monomer at pH 6.5-10, and consequently p-aminobenzoate induces dimerization in the equilibrium state of D-amino acid oxidase. The interaction energy of two subunits of the dimer is stabilized by the binding of p-aminobenzoate by 1-2 kcal/ mole over the pH range studied.
4. The binding sites of the quasi-substrate, p-aminobenzoate, in the dimer and the intersubunit binding site of the dimer are clearly different, because p-aminobenzoate induces dimerization of the enzyme.
5. The pK values of ionizing groups in the free monomer and the free dimer which participate in the binding of the competitive inhibitor, p-aminobenzoate, are approx-imately the same, 8.7, as determined from the pH dependence of the affinity of the inhibitor for the enzyme. Furthermore, no pK for the enzyme-inhibitor complex in the pH range 6.5-10 was observed.
6. There is no interaction between the two ionizing groups of the dimer during protonation-deprotonation, because a theoretical equation involving no cooperativity between the two ionizing groups in the dimer explains the results well.View full abstractDownload PDF (914K) -
Keiko KOBAYASHI, Harold P. MORRIS, Nobuhiko KATUNUMA1976 Volume 80 Issue 5 Pages 1085-1089
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe ornithine aminotransferase [EC 2. 6. 1. 13] content of Morris hepatoma 44 is about 15 times higher than that in normal liver. The turnover rates of ornithine amino-transferase in hepatoma 44 and host liver were determined using L-[14C] leucine. Studies on the incorporation of radioactive leucine into ornithine aminotransferase in rats bearing hepatoma 44 showed that the rate of synthesis of this enzyme in the hepatoma was about 5-fold higher than that in host liver. The half-life of ornithine aminotransferase in host liver was 0.98 day, which was the same as that in normal liver, whereas that in hepatoma 44 was 3.5 days. The rate constant of degradation of ornithine aminotransferase in hepatoma 44 was significantly less than that in host liver. These results show that the high ornithine aminotransferase content of hepatoma 44 is due to both increase in its rate of synthesis and decrease in its rate of degradation.View full abstractDownload PDF (413K) -
Junko IGARASHI, Norio HAYASHI, Goro KIKUCHI1976 Volume 80 Issue 5 Pages 1091-1099
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSHepatic δ-aminolevulinate (ALA) synthetase was induced in mice by the administration of allylisopropylacetamide (AIA) and 3, 5-dicarbethoxy-1, 4-dihydrocollidine (DDC. In both cases, a significant amount of ALA synthetase accumulated in the liver cytosol fraction as well as in the mitochondria. The apparent molecular weight of the cytosol ALA synthetase was estimated to be 320, 000 by gel filtration, but when the cytosol ALA synthetase was subjected to sucrose density gradient centrifugation, it showed a molecular weight of 110, 000. In the mitochondria, there were two different sizes of ALA synthetase with molecular weights of 150, 000 and 110, 000, respectively ; the larger enzyme was predominant in DDC-treated mice, whereas in AIA-treated mice and normal mice the enzyme existed mostly in the smaller form. When heroin was injected into mice pretreated with DDC, the molecular size of the mitochondria) ALA synthetase changed from 150, 000 to 110, 000. The half-life of ALA synthetase in the liver cytosol fraction was about 30 min in both the AIA-treated and DDC-treated mice. The half-life of the mitochondrial ALA synthetase in AIA-treated mice and normal mice was about 60 min, but in DDC-treated mice the half-life was as long as 150 min. The data suggest that the cytosol ALA synthetase of mouse liver is a protein complex with properties very similar to those of the cytosol ALA synthetase of rat liver, which has been shown to be composed of the enzyme active protein and two catalytically inactive binding proteins, and that ALA synthetase may be transferred from the liver cytosol fraction to the mitochondria with a size of about 150, 000 daltons, followed by its conversion to enzyme with a molecular weight of 110, 000 within the mitochondria. The process of intramitochondrial enzyme degrada-tion seems to be affected in DDC-treated animals.View full abstractDownload PDF (723K) -
Kiyoshi SHIGA, Kihachiro HORIIKE, Akio ISOMOTO, Toshio YAMANO1976 Volume 80 Issue 5 Pages 1101-1108
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSTo study the interaction between D-amino acid oxidase [EC 1. 4. 3. 3] and quasi-substrates such as benzoate and o-, m-, and p-aminobenzoate, visible circular dichroism spectra (CD spectra) were measured and the binding rate and affinity of o-aminobenzoate to the enzyme were observed by following the absorption changes at various wavelengths.
We found a new CD band around 560nm, corresponding to the charge-transfer complexes which result from the formation of aminobenzoate complexes with the enzyme. The ellipticity of this band was positive for the p-aminobenzoate complex, but negative for the o- and m-aminobenzoate complexes.
Crossover points in CD spectra were observed at 470nm for the m-aminobenzoate complex and at 475nm for the o-aminobenzoate complex. They probably resulted from overlapping of the positive CD band of FAD bound with the enzyme and the negative CD band of the charge-transfer complex.
We propose that the amino group in aminobenzoate, not the π-electrons of the benzene ring, is the electron donor in the charge-transfer complex and that the position of the amino group is very important for the charge-transfer interaction.
The binding rate and affinity of o-aminobenzoate to the enzyme were determined using the absorption changes at 370nm (380nm), caused by the modification of electronic states of FAD bound with the enzyme, and at 550 nm (565nm), caused by the formation of the charge-transfer complex of o-aminobenzoate with the enzyme. No differences between these parameters with wavelength were observed. This independence of wavelength simplifies discussion of the experimental data obtained from absorption changes.View full abstractDownload PDF (601K) -
Yoosuke YAMADA, Akio INOUE, Shizuo WATANABE1976 Volume 80 Issue 5 Pages 1109-1115
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS2, 4-Dinitrophenol (DNP) was found to cause a “clearing response” of myosin B in a medium in which “superprecipitation” of myosin B would otherwise take place. The effect of actin concentration on Mg-ATPase [EC 3. 6. 1. 3] of HMM was studied in the presence and absence of DNP. The results indicate that DNP causes an increase rather than a decrease in the affinity of HMM for actin, and that it causes a decrease only in the actin-activated portion of the Mg-ATPase activity. Using a light-scattering technique, it was shown that neither the ATP-induced dissociation of acto-HMM nor subsequent reassociation is significantly affected by the presence of DNP. As for the formation of the myosin-phosphate-ADP complex in the myosin-ATPase reaction, it was shown that formation of the reactive complex is, not affected by DNP. It can thus be concluded that DNP inhibits the decomposition of the actomyosin-phosphate-ADP complex, which is thought to be coupled with superprecipitation.View full abstractDownload PDF (475K) -
Hidenori YOSHINO1976 Volume 80 Issue 5 Pages 1117-1128
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. Two moles of 2-hydroxy-5-nitrobenzyl group bound selectively to one mole of heavy meromyosin when it was treated with 2-hydroxy-5-nitrobenzyl bromide, a specific reagent for tryptophanyl residues. The binding with ADP, the size of the initial burst of P; liberation and the difference absorption spectrum with and without ADP of the bound 2-hydroxy-5-nitrobenzyl groups were measured with heavy mero-myosin modified with various amounts of reagent. The properties of the modified heavy meromyosin did not change until the molar binding ratio of the reagent, ra, was about 1, but the properties changed remarkably when rH increased from 1 to 2.
2. Subfragment-1 was prepared from the modified heavy meromyosin by trypsin [EC 3. 4. 21. 4] digestion. The molar binding ratio of the reagent in subfragment-1, rS, was found to be less than 0.1 when rH of the starting heavy meromyosin was less than 0.8. However, rS was about 0.5 in subfragment-1 prepared from heavy meromyosin of rH about 2. The results indicate that only one mole of 2-hydroxy-5-nitrobenzyl group, which was bound with lower reactivity than the other, was bound to a head part of heavy meromyosin.
3. Subfragment-1 fraction prepared from the modified heavy meromyosin could be separated into two fractions by DE-32 cellulose column chromatography; the sub-fragment-1 portion which eluted later showed a higher rS than that eluted in front. The binding with ADP, the size of the initial burst of P1 liberation and the difference absorption spectrum induced by ATP were measured with the modified subfragment-1 separated by DE-32 cellulose column chromatography. The ADP-binding ability and the size of the initial burst were not dependent on rS, and coincided with those of subfragment-1 prepared from unmodified heavy meromyosin.
4. The results of ADP binding studies suggest that heavy meromyosin is constituted from nonidentical subunits, and that there is an interaction between them which controls the ADP binding. Two tryptophanyl residues having specific reactivity toward 2-hydroxy-5-nitrobenzyl bromide are assumed to be involved in the interaction.View full abstractDownload PDF (956K) -
Toshio KITAZAWA1976 Volume 80 Issue 5 Pages 1129-1147
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIt was investigated whether mitochondria play a significant role in the physiological regulation of the contractile process by Ca2+ in cardiac muscle in comparison with the sarcoplasmic reticulum (SR). Ca uptake activities of chicken cardiac SR and rabbit cardiac mitochondria were measured by means of centrifugation, dual-wave-length spectrophotometric and Millipore filtration methods. The maximum Ca uptake capacity of cardiac SR was usually 50-60 nmoles/mg protein and the apparent binding constant was 2.0×106 M-1. The apparent Ca-binding constant of cardiac mitochondria under limited loading conditions was 2.4×105 M-1 at pH 7.4 and 5.9×104 M-1 at pH 6.8. In the presence of 100 μM Ca2+ at 28-29°, the estimated initial rate of Ca uptake of cardiac SR ranged from 20 to 30 nmoles Ca/mg•sec, while that of mitochondria was 4.6 nmoles Ca/mg-sec under limited loading conditions at pH 7.4 and 0.64 nmoles Ca/mg-sec under massive loading conditions at pH 6.8, which was much closer to physiological conditions. In the presence of low Ca2+ concentrations, the initial rate of Ca uptake of cardiac SR was 0.5 nmoles Ca/mg-sec at 3.5×10-7 M Ca2+ and that of mitochondria under massive loading conditions at 1×10-6 M Ca2+ was 0.02 nmoles Ca/mg-sec at pH 7.4 and 0.004 nmoles Ca/mg-sec at pH 6.8. The Ca uptake activ-ities were also examined using glycerol-extracted cardiac muscle fibers. Cardiac SR, 1.7mg/ml, reduced the tension of maximally contracted cardiac muscle fibers to a level corresponding to about 30% of maximum tension, but in the presence of 14.3mg/ml of mitochondria the maximum tensions of both skeletal muscle and cardiac muscle fibers were maintained for at least 3 min.View full abstractDownload PDF (1441K) -
Yasuo OGAWA, Setsuro EBASHI1976 Volume 80 Issue 5 Pages 1149-1157
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSβ, γ-Methylene adenosine triphosphate (AMPOPCP) has two effects on fragmented sarcoplasmic reticulum (FSR), i.e., inhibition of the rate of Ca uptake and the induction of Ca release from FSR filled with Ca. The Ca release brought about by AMPOPCP has many features in common with the mechanism of Ca-induced Ca release: i) it is inhibited by 10 mm procaine; ii) the amount of Ca release increases with increase in the extent of saturation of FSR with Ca; iii) increase of the Ca concentration in the medium facilitates the release of Ca. However, no facilitation of Ca release upon decrease of Mg concentration in the medium is observable.
AMPOPCP and caffeine potentiate each other remarkably in their Ca-releasing action, irrespective of the kind of substrate. From the mode of action of AMPOPCP on the rate of Ca uptake, the amount of phosphorylated intermediate (EP), and the effect on Sr release, it is suggested that the state of the FSR-ATP complex is crucial for Ca-induced Ca release.View full abstractDownload PDF (621K) -
IV. Tissue Specificity in Oxidation of Leucine, Tyrosine, and LysineChiseko NODA, Akira ICHIHARA1976 Volume 80 Issue 5 Pages 1159-1164
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn vitro and in vivo studies were made on the tissue specificity of oxidation of the ketogenic amino acids, leucine, tyrosine, and lysine.
In n vitro studies the abilities of slices of various tissues of rats to form 14C02 from 14C-amino acids were examined. With liver, but not kidney slices, addition of α-ketoglutarate was required for the maximum activities with these amino acids. Among the various tissues tested, kidney had the highest activity for lysine oxidation, followed by liver; other tissues showed very low activity. Kidney also had the highest activity for leucine oxidation, followed by diaphragm ; liver and adipose tissue had lower activities. Liver had the highest activity for tyrosine oxidation, but kidney also showed considerable activity; other tissues had negligible activity.
In in vivo studies the blood flow through the liver or kidney was stopped by ligation of the blood vessels. Then labeled amino acids were injected and recovery of radioactivity in respiratory 14C02 was measured. In contrast to results with slices, no difference was found in the respiratory 14CO2 when the renal blood vessels were or were not ligated. On the contrary ligation of the hepatic vessels suppressed the oxidations of lysine and tyrosine completely and that of leucine partially. Thus in vivo, lysine and tyrosine seem to be metabolized mainly in the liver, whereas leucine is metabolized mostly in extrahepatic tissues and partly in liver. Use of tissue slices seems to be of only limited value in elucidating the metabolisms of these amino acids.View full abstractDownload PDF (451K) -
Miyako ABE, Makoto MATSUDA1976 Volume 80 Issue 5 Pages 1165-1171
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe effects of DL-penicillamine (DL-PeA), hydrazine and toxopyrimidine (TXP, 2-methyl-6-amino-5-hydroxymethylpyrimidine) on γ-aminobutyric acid (GABA) metabolism in mouse brain were studied. All these compounds inhibited the activity of glutamate decarboxylase [EC 4. 1. 1. 15] (GAD) and slightly inhibited that of 4-aminobutyrate : 2-oxoglutarate aminotransferase [EC 2. 6. 1. 19] (GABA-T). In contrast, very different effects were observed on GABA levels; hydrazine caused a marked increase, DL-PeA had no effect, and TXP caused a slight decrease in the content of the amino acid. These results could be described by an equation which related the excitable state to changes in the flux of the GABA bypass. Since the values obtained from the equation clearly reflect the seizure activity, it is suggested that the decreased GABA flux might be a cause of convulsions induced by these drugs.View full abstractDownload PDF (494K) -
Kenji TAKAHASHI1976 Volume 80 Issue 5 Pages 1173-1176
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSNinhydrin (1, 2, 3-indantrione monohydrate) was shown to react with the guanidino group of Nα-benzyloxycarbonylarginine under mild conditions (pH 8.0, 25°). When ribonuclease A [EC 3. 1. 4. 22] was reacted with ninhydrin under similar conditions, rapid inactivation took place with concomitant modification of arginine and lysine residues. Specific modification of arginine residues in the enzyme could be achieved by reversible blocking of amino groups with citraconic anhydride. Ribonuclease T, [EC 3. 1. 4. 8] was also inactivated rapidly by ninhydrin under similar conditions. In this case, the single arginine residue (Arg-77) and the amino groups of the N-terminal alanine and lysine-41 appeared to be specifically modified, Other amino acid residues did not appear to be significantly modified by ninhydrin in either of these enzymes. Ninhydrin thus can be used for the specific modification of arginine residues in pro-teins under mild conditions by reversibly blocking amino and, possibly, thiol groups.View full abstractDownload PDF (289K) -
Mitsuhiro HIGASHIDA, Yasuo MUKOHATA1976 Volume 80 Issue 5 Pages 1177-1179
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe effect of Mg2+ on the binding of adenylates to isolated chioroplast coupling factor 1 (CF1) was studied using CD spectrometry and ultrafiltration. At adenylate concentrations smaller than 100 μM, one mole of CF1 binds three moles of ATP (or ADP) regardless of the presence of Mg2+. In the presence of Mgt+, the first two ATP's bind to CF1 independently with the same binding constant of 2.5×10-1 μM-1, then the third ATP binds with a much higher affinity of 10 μM-1. In the absence of Mg2+, the first ATP binds to CF, with a binding constant of 2.5×10-1 μM-1, then the other two ATP's bind less easily with the same binding constant of 4.0×10-2 μM-1. The binding mode of ADP to CF1 is quite similar to that of ATP. In the presence of Mg2+, the binding constants of the first two ADP's are both 7.6×10-2 μM-1, that of the third ADP being 4.0 μM-1. In the absence of Mg2+, the binding constant of the first ADP is 7.6×10-2 μM-1, the constants of the other two ADP's both being 4.0×10-2 μm-1. AMP caused a negligible change in CD.View full abstractDownload PDF (243K) -
Akemi SUZUKI, Shizuo HANDA, Tamio YAMAKAWA1976 Volume 80 Issue 5 Pages 1181-1183
Published: November 25, 1976
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe method of separation of glucosylceramide by HPLC was reported. Glucosyl-ceramide was perbenzoylated and separated on a packed μBondapack C18 column, using methanol as eluting solvent.
The pattern obtained by HPLC closely resembled that obtained by GLC of the TMS-glucosylceramide, and reflected the molecular species of fatty acid components.
This method is reproducible, and sensitive as GLC. This method also can be used for analysis of higher glycolipids.View full abstractDownload PDF (204K)
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