巻号一覧
88 巻, 3 号
選択された号の論文の37件中1～37を表示しています
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Purification and CharacterizationAkihiko MORIYAMA, Kenji TAKAHASHI1980 年 88 巻 3 号 p. 619-633
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーTwo types of cathepsin D (cathepsins D-I and D-II) were purified from rhesus monkey lung to homogeneity as judged from disc gel electrophoresis. Cathepsin D-I was purified about 2, 000-fold with a 5.1% yield while cathepsin D-II was purified about 2, 300-fold with a 14.3% yield. Both cathepsins D were rich in the lysosome fraction of the lung, but appeared to be present in part extracellularly. Both showed a molecular weight of about 35, 000 on Sephadex G-100 chromatography, and about 41, 000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cathepsin D-I showed the maximal activity on bovine hemoglobin and albumin at pH 3.4 and 4.0, respectively. It was most stable in the pH range of 5 to 7, but was rather unstable outside this pH range. Cathepsin D-II was quite similar in properties to that from Japanese monkey lung (Moriyama, A. & Takahashi, K. (1978) J. Biochem. 83, 441-451), and was remarkably stable in the pH range of 1-9. Under the conditions used, it retained at least 80% of the original activity when incubated at 37°C for 20 h in this pH range. This stability seems to allow cathepsin D-II to be fairly active even at pH 1.0. Both cathepsins D acted on protein substrates fairly similarly and hydrolyzed hemoglobin most rapidly among the proteins tested. They did not hydrolyze N-acetyl-L-phenylalany1-3, 5-di-iodotyrosine. Upon incubation with the oxidized B-chain of insulin, both cathepsins D hydrolyzed the 14Ala-15Leu, 15Leu-16Tyr, 16Tyr-17Leu, 24Phe-25Phe, and 25Phe-26Tyr bonds at both pH 3.0 and 5.0. In addition, cathepsin D-II hydrolyzed the 11Leu-12Val and 26Tyr-27Thr bonds at pH 3.0 and the 2Val-3Asn bond at pH 5.0. Both cathepsins D were inactivated by acid proteasespecific inhibitors such as pepstatin, 1, 2-epoxy-3-(p-nitrophenoxy)propane, p-bromophenacyl bromide, and diazoacetyl-DL-norleucine methyl ester, although cathepsin D-II was much less susceptible to these reagents except p-bromophenacyl bromide.抄録全体を表示PDF形式でダウンロード (1480K) -
V. Purification, Characterization, and Amino-Terminal Sequence Determination of Crab-Eating Monkey Pepsinogens and PepsinsTakashi KAGEYAMA, Kenji TAKAHASHI1980 年 88 巻 3 号 p. 635-645
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーPepsinogens were purified from the gastric mucosa of the crab-eating monkey, Macaca fascicularis. Eight pepsinogens were shown to be present disc-electrophoretically and they were termed pepsinogens I-a, I-b, III-1-a, III-1-b, III-2-a, III-2-b, III-3, and C, based on the nomenclature used for Japanese monkey pepsinogens. The molecular weights were 43, 000 for pepsinogens I-a and I-b, 40, 000 for pepsinogens III-1-a, III-1-b, III-2-a, III-2-b, and III-3, and 38, 000 for pepsinogen C, as determined by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis. Pepsinogens I-a and I-b contained carbohydrate amounting to about 4-5% by weight. Each was activated to pepsin by acidification at pH 2.0. Pepsinogen III-1 (a mixture of III-1-a and III-1-b) yielded a single pepsin, i.e. pepsin III-1, and pepsinogen III-2 (a mixture of III-2-a and III-2-b) also gave a single pepsin, i.e. pepsin III-2. The molecular weights were estimated to be 38, 000 for pepsins I-a and I-b, 35, 000 for pepsins III-1, III-2, and III-3, and 34, 000 for pepsin C. Optimal pHs toward acid-denatured hemoglobin were 1.9, 2.3, 2.0, 2.0, and 2.3 for pepsins I-a, III-1, III-2, III-3, and C, respectively. Pepstatin, diazoacetyl-DL-norleucine methyl ester (DAN), 1, 2-epoxy-3-(p-nitrophenoxy)propane (EPNP), and p-bromophenacyl bromide inhibited each pepsin. Amino acid compositions of the pepsinogens and pepsins were determined. Pepsinogen C and pepsin C were distinct from the other pepsinogens and pepsins in their high ratios of glutamic acid to aspartic acid, and leucine to isoleucine. Amino acid sequences of the amino (N)-terminal 14 residues of pepsinogens were determined by the manual Edman procedure. One to three substitutions of amino acids were observed in the 14-residue segments among the pepsinogens except for pepsinogen C. There were 7 amino acid substitutions between pepsinogens C and III-3. These results suggest that the amino acid substitutions in the N-terminal region contribute considerably to the heterogeneity of pepsinogens.抄録全体を表示PDF形式でダウンロード (1170K) -
Göran LARSON, Bo E. SAMUELSSON1980 年 88 巻 3 号 p. 647-657
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe non-acid glycosphingolipids of cord blood erythrocytes, pooled from blood groups O and A respectively, were characterized by mass spectrometry in combination with immunologic and thin-layer chromatographic analyses. The glycosphingolipid pattern was compared to that of adult erythrocytes. Just as for adult blood, the major glycosphingolipid species were lactosylceramide and globotetraosylceramide (globoside). The triglycosylceramide fraction was quantitatively smaller in cord red blood cells and was also enriched in a triglycosylceramide with a terminal hexosamine, as conclusively shown by mass spectrometry. The amount of blood group A and H active glycosphingolipids appeared to be less in cord blood cells compared to adult cells as glycolipids with longer, probably branched chain structures were not detected. In contrast, increased amounts of penta- and hexaglycosylceramides lacking fucose and possibly being biosynthetic precursor substances to the ordinary blood group A and H glycosphingolipids were found typical for cord blood cells.抄録全体を表示PDF形式でダウンロード (1098K) -
An Improved Assay for cGMP Phosphodiesterase in Myxococcus xanthusJim HO, A. H. WARNER, H. D. McCURDY1980 年 88 巻 3 号 p. 659-662
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーAmmonium bicarbonate was found useful in extracting a variety of radiolabeled compounds from thin-layer chromatographic plates. The technique significantly increased the sensitivity of the assay for cyclic nucleotide phosphodiesterases. This method was used to show unequivocally, the presence of cGMP phosphodiesterase in vegetative cells of Myxococcus xanthus.抄録全体を表示PDF形式でダウンロード (290K) -
Tae Young LEE, Jin JUNG, Pill-Soon SONG1980 年 88 巻 3 号 p. 663-668
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーα-Crustacyanin exhibits two CD extrema with negative and positive bands at 690 and 583 nm in phosphate buffer, respectively. The CD spectrum is interpreted in terms of dipoledipole coupling between the transition moments of the two astaxanthin molecules on each subunit. The CD splitting yields an exciton bandwidth of 2800cm-1, corresponding to an inter-chromophore distance of ca. 13 Å in which the two astaxanthin molecules exist in a dimeric array with a mutual orientation angle of ca. 90°. The SDS denaturation completely abolishes the long wavelength CD splitting, while 2M NaCl reduces the overall CD intensity without destroying the split CD spectrum. It is suggested that the characteristic CD extrema at 583 and 690 nm arise from the intra-subunit astaxanthin-astaxanthin coupling. The binding site for astaxanthin contains one or more tryptophan residues, as the tryptophan fluorescence is quenched by energy transfer from the tryptophan to the prosthetic group in the native form of the carotenoprotein. The strong red shift (λmax 624nm) of the native protein relative to the denatured pigment (λmax 487nm) is probably due to interactions between tryptophan residue(s) and the chromophore molecules through dipole-dipole or partial charge transfer forces.抄録全体を表示PDF形式でダウンロード (411K) -
Hiroshige TSUZUKI, Tatsushi OKA, Kazuyuki MORIHARA1980 年 88 巻 3 号 p. 669-675
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーTrypsin [EC 3. 4. 21. 4] and papain [EC 3. 4. 22. 2] catalyzed the coupling between Cbz-Arg-OH and Leu-X (X=-NH2, -OEt, -OBut, or -NH_??_) in solution. The optimum pH for synthesis by trypsin and by papain was 6.5-7.0 and 5.5, respectively. Papain possessed reactivity several times higher than that of trypsin. To shift the reaction toward synthesis, the concentration of amine components must be at least several times higher than that of the carboxyl component (Cbz-Arg-OH). The effect of the concentration of Leu-X depended upon the nature of X; higher concentrations were required in the following order: -NH2>-OEt, -OBut>-NH_??_. High concentrations of organic cosolvents were also significant for promoting the synthesis.抄録全体を表示PDF形式でダウンロード (427K) -
Akimasa SHIOTANI, Takahide WATANABE, Ichiro MATSUOKA, Takao NAKAMURA1980 年 88 巻 3 号 p. 677-683
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーLinoleate hydroperoxide and linoleate at concentrations of 100-140 nmol/mg protein activated state 4 respiration of rat heart mitochondria 4.2-fold, increased the apparent enthalpy change of the respiration per gram atom of oxygen consumed from -148 to -226 kJ/O and completely inhibited oxidative phosphorylation. Methyl linoleate hydroperoxide or methyl linoleate did not show the same effects. Further addition of linoleate hydroperoxide or linoleate induced oligomycin-insensitive Mg-ATPase to a level 5 or 2 times, respectively, that obtained with 120μM dinitrophenol, accompanied by clearing of the mitochondrial suspension and release of malate dehydrogenase from the matrix. Methyl linoleate hydroperoxide had the same effects except that the induced Mg-ATPase activity retained oligomycin sensitivity. Methyl linoleate did not show either effect.抄録全体を表示PDF形式でダウンロード (476K) -
Takashi MURAMATSU, Gabriel GACHELIN, Francois JACOB1980 年 88 巻 3 号 p. 685-688
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーEndo-β-N-acetylglucosaminidase H released four major oligosaccharides from high-mannose glycopeptides prepared from embryonal carcinoma cells. The oligosaccharides were indistinguishable from (Man)9GlcNAc, (Man)8GlcNAc, (Man)7GlcNAc, and (Man)6GlcNAc isolated from fibroblasts. This result suggests that the biosynthetic pathway of asparagine-linked oligosaccharides in early embryonic cells is controlled as in adult cells, at least to the initial stage of processing of the nascent oligosaccharide transferred from lipid-linked intermediate.抄録全体を表示PDF形式でダウンロード (296K) -
Yasuo KITAGAWA, Etsuro SUGIMOTO1980 年 88 巻 3 号 p. 689-693
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーIn order to estimate the in vivo translational activity of mitochondria without using cycloheximide, we developed a selective separation procedure for the mitochondrial translation products. The effects of cycloheximide and isotopic dilution kinetics on the precursor leucine pool indicate that the pH 11.5 insoluble mitochondrial fraction is greatly enriched in mitochondrial translation products.抄録全体を表示PDF形式でダウンロード (371K) -
Hiroshi KANAZAWA, Yoshie HORIUCHI, Michiko TAKAGI, Yumiko ISHINO, Masa ...1980 年 88 巻 3 号 p. 695-703
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe defective coupling factor F1 ATPase from a mutant strain (KF 11) of Escherichia coli was purified to a practically homogeneous form. The final specific activity of Mg2+-ATPase was 6-9 units/mg protein, which is about 10-15 times lower than that of F1 ATPase from the wild-type strain. The mutant F1 had a ratio of Ca2+-ATPase to Mg2+-ATPase of about 3.5, whereas the wild-type F1 had a ratio of about 0.8. The mutant F1 was more unstable than wild-type F1: on storage at -80°C for 2 weeks, about 80% of its activity (dependent on Ca2+ or Mg2+) was lost, whereas none of the activity of the wild-type F1 was lost.
The following results indicate that the mutation is in the β subunit. (i) High Mg2+-ATPase activity (about 20 units/mg protein) was reconstituted when the β subunit from wild type F1 was added to dissociated mutant F1 and the mixture was dialyzed against buffer containing ATP and Mg2+. (ii) Low ATPase activity having the same ratio of Ca2+-ATPase to Mg2+-ATPase as the mutant F1 was reconstituted when a mixture of the β subunit from the mutant F1 and the α and γ subunits from wild-type F1 was dialyzed against the same buffer. (iii) Tryptic peptide analysis of the β subunit of the mutant showed a difference in a single peptide compared with the wild-type strain.抄録全体を表示PDF形式でダウンロード (1843K) -
Yoshimi YAMAMOTO, Kenji NISHIMURA1980 年 88 巻 3 号 p. 705-713
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーA β-galactosidase [EC 3. 1. 23] catalyzing the hydrolysis of GM1-ganglioside was purified from porcine spleen to a homogeneous form. By applying a hydrophobic chromatography procedure as the first purification step, the enzyme could be purified through subsequent purification steps as a dissociated form. The purified enzyme was a monomer with an apparent molecular weight of 70, 000-74, 000 at neutral pH and associated to a dimer with an apparent molecular weight of 158, 000-160, 000 at acidic pH, near optimal for its activity (pH 4.6). It had specific activities of 1, 820μmol/mg/h towards GM1 with an apparent Km of 3.18×10-5M, 1, 880μmol/mg/h towards lactosylceramide with an apparent Km of 1.99×10-4M, and 1, 340μmo1/mg/h towards p-nitrophenyl-β-galactopyranoside (pNp-β-galactoside) with an apparent Km of 2.14×10-4M. Kinetic studies suggested that common catalytic site (s) cleaved the two natural substrates mentioned above.抄録全体を表示PDF形式でダウンロード (1217K) -
Shuichi TSUJI, Mitsuru TAKANAMI, Kazutomo IMAHORI1980 年 88 巻 3 号 p. 715-724
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーAs the first step in the process of RNA synthesis, RNA polymerase binds to a specific site (promoter) and forms an open complex. In this process, it is considered that the structure of DNA is changed to an unidentified form. We investigated the structure of this DNA, which consists of an open complex, by means of CD. For this purpose, we used very stable RNA polymerase (of T. thermophilus HB 8) and the fd-RF-DNA fragment (Hap-Hga V), which has only one promoter. We have confirmed that the complex of the holo enzyme with Hap-Hga V fragment at 50°C is an open complex.
We obtained the CD spectral difference between the open complex and its constituents for the first time. The observed CD difference spectra in the UV region (250-300 nm) were compared with the theoretical difference CD. It was deduced that the DNA of the open complex may be melted around the initiation point over a rather longer range than expected.抄録全体を表示PDF形式でダウンロード (1262K) -
I. Purification and Subunit StructureSeisuke HATTORI, Kentaro IWASAKI1980 年 88 巻 3 号 p. 725-736
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe high molecular weight form of the polypeptide chain elongation factor-I (EF-1H) from pig liver was purified to an apparently homogeneous state. The procedure included aqueous two-phase separation, ammonium sulfate fractionation, four successive column chromatographies on Sephadex G-200, CM-Sephadex C-50, hydroxylapatite and octyl-Sepharose CL-4 B, and glycerol density gradient centrifugation. By this procedure, the specific activity of EF-1H increased about 60-fold with a recovery of the total activity of 6%, as compared to the material obtained by aqueous two-phase separation followed by ammonium sulfate frac-tionation.
Purified EF-1H was analyzed by polyacrylamide gel electrophoresis under non-denaturing conditions and glycerol gradient centrifugation, revealing that it is apparently homogeneous and has both EF-1 α and EF-1 βγ activities. The subunit structure of EF-1H was investigated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate as well as two-dimensional gel electrophoresis, which indicated that EF-1H consists of three different subunits, i.e., EF-l α, EF-1 β, and EF-1 γ, in an equimolar ratio. The Stokes radius and the sedimentation coefficient of EF-1H were estimated to be 5.9 nm and 6.2 S, respectively, from which the molecular weight of EF-1H was calculated to be about 157, 000. This value is close to the sum of the molecular weights of EF-1 α (53, 000), EF-l β (30, 000), and EF-1 γ (53, 000). Thus, we concluded that EF-1H is a monomer of a 1:1:1 complex of EF-1 α, EF-1 β, and EF-1 γ, or EF-1 αβγ and its molecular weight is 136, 000. This conclusion was further confirmed by measuring the amounts of EF-1 α and EF-1 βγ in EF-1H by enzymatic assays. The amino acid composition of EF-1H was determined, and the results revealed that there was a close resemblance between the values of EF-1H and those of EF-1 αβγ, which were calculated from the reported values for EF-1 α, EF-1 β, and EF-1 γ.抄録全体を表示PDF形式でダウンロード (943K) -
Showbu SATO, Kayoko NAKAZAWA, Takahisa SHINOMIYA1980 年 88 巻 3 号 p. 737-747
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーA DNA methylase was purified in a homogeneous state from a extremely thermophilic bacterium, Thermus thermnophilus HB 8, by chromatography on, successively, phosphocellulose, CM-cellulose, and heparin-Sepharose. The molecular weight of the enzyme was determined to be about 44, 000 by gel filtration on a Sephadex G-100 column and 41, 000 by SDS-poly-acrylamide gel electrophoresis, and these findings suggest a single polypeptide enzyme. The enzyme develops maximum activity around pH 7.4 and at 70°C. Enzymatic activity is completely inhibited by 0.2M NaCl or 2mM HgCl2. The enzyme transfers methyl groups from S-adenosyl-L-methionine to a double stranded DNA. The sole product of the reaction was identified as N-6-methyl adenine after hydrolysis of the DNA with formic acid. The enzyme kinetics obey the Michaelis-Menten equation and Km values for S-adenosylmethionine and lambda phage DNA were determined to be 0.8μM and 10μg/ml, respectively. The enzyme does not transfer methyl groups to TthHB 8 I endonuclease digested DNA as well as the host (T. thermophilus HB 8) DNA. The number of methyl groups of the fully methylated øX 174 RF DNA was about twice as many as TthHB 8 I endonuclease sites on the DNA. The distribution of the methyl groups of øX 174 RF DNA among the HaeIII fragments was the same as that of TthHB81 endonuclease sites, suggesting that this DNA methylase is the other component of the modification-restriction system including TthHB 8 I endonuclease. The enzyme probably recognizes the sequence, 5'-TCGA-3', in a double stranded DNA and probably methylates adenine in the above sequence.抄録全体を表示PDF形式でダウンロード (2626K) -
Yoh SANO1980 年 88 巻 3 号 p. 749-755
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe kinetics of α-crystallin reaggregation in the presence of calcium ions were investigated by monitoring changes in optical density at 320 nm. α-Crystallin showed a critical concentration. In the initial stages, reaggregation and deaggregation of α-crystallin may be essentially fully reversible in the presence of high levels of calcium ions. The initial rate of reaggregation was strongly calcium ion-dependent. The kinetics of α-crystallin reaggregation revealed a pseudo-first order time dependence. This is most easily explained by postulating very rapid formation of the initial complex for α-crystallin reaggregation (nucleation). These studies indicate that reaggregation of α-crystallin occurs by a pathway involving a nucleation phase followed by an elongation phase, that the formation of the small active initiator, presumably α-crystallin dimer or some species formed from it (i.e., intermediate high molecular weight component) is very fast, and that the growth of these active initiators is biphasic.抄録全体を表示PDF形式でダウンロード (523K) -
Kazunobu MATSUSHITA, Mamoru YAMADA, Emiko SHINAGAWA, Osao ADACHI, Mino ...1980 年 88 巻 3 号 p. 757-764
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe location and function of ubiquinone in the electron transport system of Pseudomonas aeruginosa grown aerobically were studied.
The reduction level of ubiquinone in the intact membrane was 36-43% in the aerobic steady state and about 65% in the anaerobic state with one substrate, but the level in the anaerobic state reached to 81% with a mixture of several substrates.
Complete removal of ubiquinone performed by extracting the lyophilized membrane particles with n-pentane containing acetone resulted in complete loss of all oxidase activities for glucose, gluconate, malate, succinate, and NADH. In the ubiquinone-depleted particles, neither cytochrome component was reduced by adding any substrate. Reincorporation of coenzyme Q9 into the depleted particles restored each oxidase activity to 60 to 80% of the original and reduction of cytochromes with substrates. The reduction kinetics of cytochromes and effect of inhibitors showed that coenzyme Q9 was incorporated at the original site in the electron transport system.
Exogenous coenzyme Q2 increased gluconate and malate oxidase activities and decreased glucose oxidase activity, when French-pressed membrane vesicles but not spheroplasts were used. Oxidizing activity for reduced coenzyme Q2 was also detected in the pressed vesicles but not in the spheroplasts.
The present results showed that ubiquinone was indispensable and located prior to cytochromes in the electron transport system. Furthermore, the homogeneity and sidedness of ubiquinone in the cytoplasmic membrane of the organism are also discussed.抄録全体を表示PDF形式でダウンロード (623K) -
Purification of Rat Liver Glycerate Kinase and Studies of Its Enzymatic and Immunological PropertiesHirokazu KATAYAMA, Yasuo KITAGAWA, Etsuro SUGIMOTO1980 年 88 巻 3 号 p. 765-773
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーGlycerate kinase was purified to near homogeneity from rat liver mitochondria. Sephadex G-100 chromatography and sodium dodecyl sulfate-gel electrophoresis showed that the enzyme is a monomer with a molecular weight of 51, 000-56, 000. Kinetic studies indicated that the reaction proceeds by the “rapid equilibrium random sequential” mechanism, and the Michaelis constants were found to be 0.032mM and 0.091mM for D-glycerate and ATP, respectively. The binding of n-glycerate specifically protected the enzyme from thermal inactivation. The dissociation constant of the enzyme•D-glycerate complex was similar to the Michaelis constant, suggesting that the protective effect of n-glycerate may be caused by the specific binding of the substrate to the active site of the enzyme. The antibody to the enzyme was prepared by immunizing a rabbit with the purified rat liver glycerate kinase. Immunological experiments indicated that the cytosol and mitochondrial enzymes are indistinguishable. It was also found by immunological studies that the increase in the cytosol and mitochondrial enzyme activity depending on dietary protein intake was proportional to the increase in enzyme protein. These results support our proposal (Kitagawa, Y., Katayama, H., & Sugimoto, E. (1979) Biochim. Biophys. Acta 582, 260-275) that cytosol and mitochondria) glycerate kinase arise from a common translation product and that dietary protein regulates the distribution of glycerate kinase to the cytosol and mitochondria.抄録全体を表示PDF形式でダウンロード (1653K) -
Fumihide ISOHASHI, Masako TERADA, Kazue TSUKANAKA, Yoko NAKANISHI, Yuk ...1980 年 88 巻 3 号 p. 775-781
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーWhen rat liver cytoplasm free of glucocorticoid receptors was dialyzed, its inhibitory effect on nuclear uptake or binding of already “activated” receptor-glucocorticoid complex increased. A macromolecular fraction and a low-molecular-weight fraction separated from the cytoplasm by gel filtration both inhibited nuclear uptake or binding of the activated complex. The macromolecular fraction was much more inhibitory than the low-molecular-weight fraction. When the two components were mixed, their inhibitory effects decreased. These results suggest that, in addition to the macromolecular translocation inhibitor(s) known to be present in rat liver cytoplasm, there is a low-molecular-weight factor(s) which is also involved in the process of translocation of the activated receptor-glucocorticoid complex to the nucleus. The mechanism of action of this modulator is unknown, but its inhibitory effect seems to be due to its direct interaction with the activated receptor-steroid complex.抄録全体を表示PDF形式でダウンロード (600K) -
II. Reconstitution of Heterotype Histone Oligomers and pH Dependency of Oligomer FormationSeiichi KAWASHIMA, Kazutomo IMAHORI1980 年 88 巻 3 号 p. 783-788
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーHistone oligomers were reconstituted by annealing from dissociated calf thymus whole histones in 2M NaCl-5M urea. The products were fractionated in terms of solubility in ammonium sulfate solution. The oligomers formed at pH 5 were heterotype histone oligomers (H2A•H2B•H3•H4)n at high ionic strength, and heterotype histone tetramer (H2A•H2B•H3•H4) at low ionic strength. The pH dependency of oligomer formation was determined. Heterotype oligomers were formed at pH 4-6 and homotype oligomers at pH 7-9.抄録全体を表示PDF形式でダウンロード (930K) -
A Proton Magnetic Resonance Study of Individual Histidine EnvironmentShigeru FUJII, Kazuyuki AKASAKA, Hiroyuki HATANO1980 年 88 巻 3 号 p. 789-796
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーResonance positions and intensities of the C(2) protons of histidyl residues (His 43 and His 106) were followed in the NMR spectrum of a protein, Streptomyces subtilisin inhibitor (MW 23, 000), in the pH range 2-9 at 30°C, in order to clarify the microenvironment of the individual histidyl residues and the acid denaturation processes of the protein.
The large difference in the 1H-2H exchange rate between the C(2) protons of the two histidyl residues indicates that, whereas His 106 is well exposed to the solvent, His 43 is highly shielded from the solvent. Protonation of His 106 occurs in the pH range 5-9, giving a pKa of 6.0±0.1. In contrast, His 43 can not be protonated in the native conformation, but its protonation occurs simultaneously with the acid denaturation of the protein in a narrow pH range 2.7-3.6, with pHmid of transition at 3.25. On the other hand, the denaturation of the His 106 environment starts at pH 5.0 and finishes at pH 2.7 with pHmid of transition at 3.7. The denaturation transitions are reversible with pH for both His 43 and His 106, but the rates of these transitions are slow (less than 25 s-1).
The Hill coefficient for the His 106 transition was found to be 0.9±0.1 in the pH range 3.5-5.0, but to be distinctively larger than unity below pH 3.5. On the other hand, the Hill coefficient for the His 43 transition was found to be 4.4±0.6 for the whole range of transition (pH 2.7-3.6). These results combined with available information about the crystal structure lead us to conclude that the transition of His 106 in the pH range 3.5-5.0 represents a local denaturation caused by the protonation of one neighboring residue, probably Glu 102, whereas the transition of His 43 occurs as a result of cooperative protonation of several residues probably including Phe 113 and Asp 52, and is a denaturation step accompanied by the destruction of the major hydrophobic core.抄録全体を表示PDF形式でダウンロード (600K) -
Hideyuki TANAKA, Ikuharu SASAKI, Kanzo YAMASHITA, Kaoru MIYAZAKI, Yuhs ...1980 年 88 巻 3 号 p. 797-806
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリー1. DNase I from porcine pancreas, if Mg2+ was present, hydrolyzed both sDNA and dDNA, whether free or bound to Sepharose. The hydrolysis rates were maximum at pH 7.5 with the bound DNAs and at pH 7.0 with the free DNAs negligible at pH 4.0 and pH 10.5 with the free and bound DNAs. The hydrolysis was completely inhibited by 50mM sodium citrate.
2. With 50mM citrate buffer (pH 4.0), DNase I was effectively adsorbed on the DNA-Se-pharoses in the absence of 5mM Mg2+. The adsorbed enzyme was effectively eluted by the buffer containing 1M KCl (eluate). The amounts of the eluted enzyme were approximately 1.5×105 units/mg DNA with sDNA-Sepharose and approximately 3.0×105 units/mg DNA with dDNA-Sepharose. This simple adsorption-elution of the pancreas extract resulted in approximately 300-fold purification of DNase I with a yield of 95%. In the eluate, the ratios in activity of trypsin, chymotrypsin and RNase to DNase I were 1/(4.0×l03), 1/(5.3×103), and 1/(4.1×102) as low as in the extract, respectively. In addition, the eluate was not contaminated by kallikrein or carboxypeptidases A and B.
3. Upon repeating the adsorption-elution described above, the adsorbing capacities of DNA-Sepharoses gradually deteriorated with the whole pancreas extract, but not with the precipitate of the extract formed on 60% ammonium sulfate saturation, which contained 90% of the DNase I. With the precipitate, one dDNA-Sepharose column was repeatedly usable at least 20-times without deterioration. The DNase I preparation thus obtained was homogeneous on SDS-polyacrylamide gel electrophoresis.
4. Conceivably, the above-mentioned adsorption of DNase I on DNA-Sepharoses was mainly due to the steric and electrostatic affinity of a relatively large moiety of the DNA molecule to the substrate-binding site, but not to the catalytic site, of the enzyme.抄録全体を表示PDF形式でダウンロード (727K) -
Tatsushi OKA, Kazuyuki MORIHARA1980 年 88 巻 3 号 p. 807-813
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe coupling between Cbz-Phe-OH and Leu-NH2 catalyzed by thermolysin was examined under various experimental conditions. The highest yield (ca. 80%) was obtained in the reaction mixture containing 0.05M each of the carboxyl and amine components and 10 μM enzyme at pH 7 and 37°C for 5 h. The reactivity was ca. 100 times higher than that of α-chymotrypsin. Amino acid derivatives or peptides were useful as amine components, though a hydrophobic or bulky amino acid residue was required at the N-terminal position. Strict stereospecificity was observed at this position. A hydrophobic or bulky amino acid residue occupying the C-terminal position of carboxyl components was also favorable for synthesis. The specificity requirements for synthesis were the same as those for hydrolysis.抄録全体を表示PDF形式でダウンロード (504K) -
Takahide WATANABE, Takao NAKAMURA1980 年 88 巻 3 号 p. 815-817
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe bioluminescence activity of Photobacterium phosphoreum was compared at different times after cell division by the methods of density gradient centrifugation and synchronous culture. The bioluminescence intensity per cell mass increased linearly at a rate of 1.5 times per doubling time. The luciferase system in the cell is continuously activated during growth, independent of cell division.抄録全体を表示PDF形式でダウンロード (184K) -
Structural Studies of Neutral OligosaccharidesHideo YOSHIMA, Seiichi TAKASAKI, Akira KOBATA1980 年 88 巻 3 号 p. 819-827
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe neutral oligosaccharide fraction obtained from the hydrazinolysate of the plasma membrane glycoproteins of calf thymocytes was shown to be a mixture of twelve oligosaccharides. Oligosaccharides A, B, and C, which released galactose on treatment with jack bean β-galacto-sidase but not with diplococcal β-galactosidase, were shown to have the structures Galβ1→3Galβ1-4G1cNAcβ1-4(Galβ1→3Ga1β1→4GIcNAc β1→2) Manα1→6 (3)[Galβ1→3Galβ1→4GlcNAcβ1→6 (Galβ1→3Galβ1→4GlcNAcβ1→2) Manα1→3 (6)]Manβ1→4GlcNAcβ1→4(Fucα1→6)GlcNAc, Galβ1→3Ga1β1→4GlcNAcβ1→4(Galβ1 3Galβ→4GlcNAcβ1→2)Manα1→6 (3) [Galβ1→3Galβ1→4GlcNAcβ1→2Manα1→3 (6)]Manβ1→4GlcNAcβ1→4 (Fucα1→6)GlcNAc, and Galβ1→3Galβ1→4G1cNAcβ1→2Manα1→6 (Galβ1→3Ga1β1→4GlcNAcβ1→2Manα1→3) Manβ1→4GlcNAcβ1→4(Fucα1→6) GlcNAc, respectively. Oligosaccharides D and E, which released galactose on treatment with either jack bean β-galacto-sidase or diplococcal β-galactosidase, were shown to have the structures Galβ1→4GlcNAcβ1→2Manα1→(Galβ1→4GlcNAcβ1→2Manα1→3) Manβ1→4GlcNAcβ1→4(Fucα1→)GlcNAc and Galβ1→4GlcNAcβ1→2Manα1→(GlcNAcβ1→2Manα1→3) Manβ1→4GlcNAcβ1→4 (Fucα1→)GlcNAc, respectively.
Five oligosaccharides (F1, G, H1, I, and J) were shown to have typical high-mannose type structures (Manα1→)n•Manβ1→GlcNAcβ1→GlcNAc, with n-values of 8, 7, 6, 5, and 4, respectively.
The structures of the remaining two oligosaccharides F2 and H2 were elucidated as GlcNAcβ1→2Manα1→(GlcNAcβ1→2Manα1→3) Manβ1→4GlcNAcβ1→4 (Fucα1→)-GlcNAc and Manα1→(Manα1→) Manβ1→(GlcNAcβ1βManα1→) Manβ1→GlcNAcβ1→GlcNAc, respectively.抄録全体を表示PDF形式でダウンロード (716K) -
Yongsok YANG, Kozo HAMAGUCHI1980 年 88 巻 3 号 p. 829-836
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーBinding of 4-methylumbelliferyl chitotetraoside ((GlcNAc)4-MeU) to hen lysozyme [EC 3. 2. 1. 17] was studied by measuring changes in fluorescence at 375 nm. Hydrolysis of (GlcNAc)4-MeU catalyzed by lysozyme was studied by measuring the release of 4-methyl-umbelliferone from (GlcNAc)4-MeU fluorimetrically, and the kinetic constants were determined in the pH range of 2 to 8 at 0.1 ionic strength and 42°C. The binding and kinetic data showed that (GlcNAc)4-MeU binds to subsites A to E (productive binding) and subsites A to D with the nonreducing sugar residue extending beyond subsite A (nonproductive binding). The fraction of the productive complex was 0.77 at pH 8.5. The pH dependence of the kinetic constants was analyzed assuming that the molecular species with ionized Asp 52 and protonated Glu 35 is active and Asp 101 participates in the binding (Phillips (1966) Sci. Am. 215, 78-90; Blake et al. (1967) Proc. Roy. Soc. B 167, 378-388), and the pK values of these groups were determined. The pK values of Asp 52, Glu 35, and Asp 101 were 3.60, 6.20, and 4.20, respectively, for free lysozyme, 3.40, 6.55, and 3.40, respectively, for the productive complex, and 3.95, 6.55, and 3.30, respectively, for the nonproductive complex. The pK values for free lysozyme were in excellent agreement with those obtained by analysis of the kinetic constants for (GlcNAc)3-MeU (Yang & Hamaguchi (1980) J. Biochem. 87, 1003-1014). The free energy of activation was 24 kcal mol-1 at pH 5.2. Comparison with the corresponding value obtained for hydrolysis of (GlcNAc)6 (Banerjee et al. (1975) J. Biol. Chem. 250, 4355-4367) suggests that the interactions of GlcNAc residues with subsites E and F in the transition state are important in lysozyme catalysis. Hydrolysis of (GlcNAc)2-MeU catalyzed by lysozyme was also studied, and the kcat/Km values for (GlcNAc)2-MeU, (GlcNAc)3-MeU, and (GlcNAc)4-MeU were compared.抄録全体を表示PDF形式でダウンロード (646K) -
Calcium Sensitivity of Clam Foot MyosinGaku ASHIBA, Takashi ASADA, Shizuo WATANABE1980 年 88 巻 3 号 p. 837-846
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリー1. The ATPase activity of clam foot myosin alone in the presence of 10mM MgCl2 was activated approximately ten-fold by 10μM free calcium ions. The calcium activation was observed in various concentrations of KCl (35-600mM) and ATP (1μM-1mM), and at various pHs (pH 6-9.4).
2. The superprecipitation and ATPase activities of clam foot myosin B were studied by conducting experiments in two different ways. In one of these, the ATP concentration was varied at a fixed concentration of MgCl2, and in the other, the MgCl2 concentration was varied at a fixed concentration of ATP. The following was found: (a) The activities responded in a biphasic manner to change in either the ATP or MgCl2 concentration, giving a peak activity around 10μM ATP or MgCl2. It is thus suggested that Mg-ATP complex is responsible for both activation and inhibition in the biphasic response. (b) When the ATP or MgCl2 concentration was higher than 100-300μM, practically no superprecipitation occurred in either the presence or absence of calcium, whereas the ATPase activity was still strongly activated by calcium.
3. Similar results to those described above (a, b) were obtained by using rabbit skeletal actoclam foot myosin in place of clam foot myosin B. Moreover, it was found that as the ATP concentration increased from 1μM to 1mM, Mg-ATPase activity of clam foot myosin in the presence of calcium increased in a monophasic manner and that it was as active as actomyosin in the presence of calcium when the ATP concentration was higher than approximately 200μM. In other words, actin-activation of myosin-ATPase was absent in the ATP concentration where no superprecipitation of actomyosin was observed.
4. Clam foot myosin contained two types of light chain subunits: LC 1 (17, 000 daltons) and LC 2 (16, 000 daltons). Only LCl was removed upon washing clam myosin with 10mM EDTA, and removal of LCI resulted in loss of the calcium sensitivity of actomyosin-ATPase.
5. In our previous report (J. Biochem. 85, 1543-1546, 1979), it was shown that removal of LC 1 from clam foot myosin also resulted in loss of the superprecipitation activity of actomyosin reconstituted from “EDTA-washed” myosin. We now provide further evidence that removal of the regulatory light chain (LC 1) results in a reversible uncoupling of ATPase reaction from superprecipitation reaction.抄録全体を表示PDF形式でダウンロード (1280K) -
I. Distribution of C-Nitrosoreductase Activity in Animal Tissues and Partial Purification of the Enzyme from Porcine LiverShigeo HORIE, Tomino WATANABE, Yasuyuki OGURA1980 年 88 巻 3 号 p. 847-857
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe subcellular distribution of NADH-p-nitrosophenol (p-NSP) reductase activity at pH 6.0 in porcine liver was studied by spectrophotometric assay. About two-thirds of the activity was found in the cytosol fraction and the pH optimum of this fraction was about 5.5. The activity at pH 5.8 of cytosol fractions from various tissues of rats, quails, frogs, carp, and scallops was also studied. All these fractions showed more or less NADH-p-NSP reductase activity but the activity of NADH-aldehyde reductase (alcohol dehydrogenase [EC 1. 1. 1. 1]) was detected only in those from liver and a few other tissues. Supernatants from sonicated cells of Bacillus subtilis and Escherichia coli also showed C-nitrosoreductase activity but were devoid of aldehyde reductase activity.
The major C-nitrosoreductase of porcine liver cytosol was purified 20- to 30-fold by fractionation with ammonium sulfate, gel filtration, and ion-exchange chromatography. The pH optimum of this preparation was 5.5 and activity was strongly inhibited by p-chloromercuribenzoate (p-CMB). The enzyme preparation was stable at 5°C for at least a week in the presence of NADH at pH 8.4. High concentrations of ammonium sulfate also stabilized the enzyme. An equilibrium between monomeric and dimeric forms of the enzyme was found and the molecular weight was estimated to be about 83, 000 and 160, 000 daltons for the monomeric and dimeric forms, respectively. The enzyme utilized NADH almost specifically and 2mol of NADH were consumed per mol of p-NSP reduced to p-aminophenol. Nitrosobenzene and aldehydes could also serve as the electron acceptor. The aldehyde reductase activity became concentrated roughly in parallel with the C-nitrosoreductase activity during the course of the purification and these two activities could not be separated even after further purification by 5'-AMP-Sepharose affinity chromatography. N-Nitroso compounds were not affected by this enzyme.抄録全体を表示PDF形式でダウンロード (820K) -
II. Multiple Forms of Liver C-Nitrosoreductase and the Identity with Alcohol DehydrogenaseMasahiro KUWADA, Shigeo HORIE, Yasuyuki OGURA1980 年 88 巻 3 号 p. 859-869
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーInvestigations were made of the multiplicity of the major C-nitrosoreductase in porcine liver cytosol catalyzing NADH-dependent reduction of p-nitrosophenol (p-NSP) to p-aminophenol (p-AmP).
A partially purified preparation prepared by precipitation with ammonium sulfate, gel filtration with Sephadex G-100, and ion-exchange chromatography on DEAE-Sephadex A-50 showed two or more apparent Km values for p-NSP and also for NADH. This preparation could be resolved into at least four subfractions having different Km values by affinity chromatography on 5'-AMP-Sepharose. Even a more purified preparation, which was obtained from the Sephadex G-100 gel filtrate by affinity chromatography followed by ion-exchange chromatography, could be resolved into multiple subfractions by isoelectric focusing in polyacrylamide gel. All nitrosoreductase subfractions extracted from the polyacrylamide gel showed NADH-aldehyde reductase (alcohol dehydrogenase [EC 1. 1. 1. 1]) activity and, except for a few minor subfractions, the two activities were in parallel. A commercially supplied, crystalline preparation of equine liver alcohol dehydrogenase also showed a similar multiplicity and the multiple subfractions had the both enzymatic activities, although the pattern of isoelectric focusing was different from those of the porcine liver preparations.
Different heat inactivation curves were observed with various preparations, but in each preparation the curve for nitrosoreductase activity always agreed with that for aldehyde reductase activity. The nitrosoreductase preparations and the alcohol dehydrogenase preparation showed very similar pH-activity curves in catalyzing NADH-dependent reduction of p-NSP. Furthermore, ethanol inhibited the NADH-p-NSP reductase reaction competitively and p-AmP inhibited the NADH-aldehyde reductase reaction competitively.
These results clearly indicate that the major C-nitrosoreductase in porcine liver was present in multiple forms having different Km values and the enzyme was identical with liver alcohol dehydrogenase.抄録全体を表示PDF形式でダウンロード (797K) -
Nagomi KUREBAYASHI, Takao KODAMA, Yasuo OGAWA1980 年 88 巻 3 号 p. 871-876
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーWe examined the effects of P1, P5-di(adenosine-5')pentaphosphate (Ap5A), a potent inhibitor of adenylate kinase, on fragmented sarcoplasmic reticulum (FSR) obtained from bullfrog skeletal muscle in view of the possible usefulness of the nucleotide in experiments with FSR to avoid complications due to contaminating adenylate kinase. Ap5A itself does not cause Ca uptake in the place of ATP. It inhibited adenylate kinase activity without affecting the Ca-ATPase or Ca uptake activity of FSR. The observed effect was a competitive inhibition of basic ATPase activity of the light fraction of FSR. Therefore, P1, P5-di(adenosine-5')-pentaphosphate represents an extremely useful tool in experiments with fragmented sarcoplasmic reticulum, such as studies of H+ movement accompanying Ca movement, ATP-ADP exchange reaction, and calorimetry of the Ca uptake process.
A rather high concentration (50 μM or more) of Ap5A is required for complete inhibition of adenylate kinase. Further, we detected 1.3-2.8 nmol of (ATP+ADP), 2-4 nmol of P1, and unidentified metal (s) in 50 nmol of Ap5A, and Ap5A is more labile to acid and molybdate than ATP.抄録全体を表示PDF形式でダウンロード (415K) -
Umeji MURAKAMI, Koki UCHIDA1980 年 88 巻 3 号 p. 877-881
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーIncubation of rat cardiac myofibrils with a myosin-cleaving protease in the presence of EDTA at 25°C caused removal of Z- and M-lines, accompanied by myofibril fragmentation. When rat cardiac muscle I-Z-I brushes were subjected to proteolysis, the protein components with the molecular weights of 55, 000 and 50, 000 were degraded by the protease. Ca2+ was not required for the ultrastructural alterations of myofibrils caused by the protease action.抄録全体を表示PDF形式でダウンロード (1368K) -
A Connectin-Like Protein from the Plasmodium Physarum polycephalumKazuho OZAKI, Koscak MARUYAMA1980 年 88 巻 3 号 p. 883-888
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーA completely sodium dodecyl sulfate-insoluble protein was obtained from plasmodia of Physarum polycephalum. The amino acid composition of this protein was very similar to that of connectin, an elastic protein of muscle. When the protein suspension was treated with 6M guanidine-HCl in the presence of 0.1M 2-mercaptoethanol, entanglements of very thin filaments, less than 5 nm in width, were observed under an electron microscope. Since the network structure is almost the same as that of isolated muscle connectin, this plasmodium protein can be regarded as forming an elastic net structure. Using an antiserum against the insoluble protein, it appeared to be located at the peripheral region of the plasmodium. This elastic net structure may act as a cytoskeleton at the cytoplasmic surface of the plasmodium cell membrane.抄録全体を表示PDF形式でダウンロード (1336K) -
Hyung Suk KIM, Tatsuya ABE, Nobuo TAMIYA1980 年 88 巻 3 号 p. 889-893
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーThe amino groups of Laticauda semifasciata III (LsIII) purified from the venom of a sea snake, Laticauda semifasciata, were acetylated with acetic anhydride. Three monoacetyl derivatives of LsIII, namely, [1-N2-acetyl-arginine]-LsIII, [23-N6-acetyl-lysine]-LsIII and [35-N6-acetyl-lysine]-LsIII, were obtained. These monoacetyl derivatives of LsIII showed the same CD spectra as that of native LsIII. [1-N2-Acetyl-arginine]-LsIII was half as active as the original toxin suggesting the importance of the net positive charge of the toxin molecule for the toxicity. [23-N6-Acetyl-lysine]-LsIII and [35-N6-acetyl-lysine]-LsIII showed no toxicity. Lysine-23 is one of the residues common to all neurotoxins, whereas lysine-35 is one of the residues found specifically among long-chain neurotoxins, although there are some exceptional toxins without lysine-23 or lysine-35.抄録全体を表示PDF形式でダウンロード (359K) -
Hideo KOCHI, Ken SERIZAWA, Goro KIKUCHI1980 年 88 巻 3 号 p. 895-904
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーChicken liver mitochondria contained two forms of phosphoenolpyruvate (PEP) carboxykinase (designated as Mt-I and Mt-II) and the chicken liver cytosol fraction contained three forms of PEP carboxykinase (designated as Sol-I, Sol-II, and Sol-III). Mt-I and Mt-II were purified to homogeneity. They both had a molecular weight of 72, 000 as judged by the sodium dodecyl-sulfate-polyacrylamide gel electrophoresis method, whereas an apparent molecular weight of 42, 000 was obtained for both enzymes when estimated by Sephadex G-100 gel filtration. Studies with a rabbit antibody against the purified Mt-I revealed that Mt-I, Mt-Il, Sol-I, and Sol-II are immunochemically identical, whereas Sol-III is immunochemically different from any of the other proteins. Genetic analogy between Mt-I and Mt-II was also suggested by gel electrophoretic analysis of their peptide maps. The content of Sol-III in the adult chicken liver was very small, whereas the livers of chick embryo and very young chick contained a considerable amount of Sol-Ill. The level of Sol-III in the adult chicken, however, could be significantly increased by the administration of hydrocortisone or isoproterenol. Apparently Sol-Ill is a cytosol-specific PEP carboxykinase which is similar to the cytosolic PEP carboxykinases of various mammals. Sol-III showed a molecular weight of about 60, 000 as estimated by gel filtration. Studies with combined use of the antibody and [3H]leucine revealed that some portion of PEP carboxykinase (Sol-I plus Sol-II) appearing in the liver cytosol corresponds to a precursor in transit to the mitochondria, although major portions of Sol-I and Sol-II appear to be accounted for by release of the mitochondrial enzymes.抄録全体を表示PDF形式でダウンロード (1501K) -
Masaharu KUBO, Yuji MATSUZAWA, Hiroshi SUDO, Katsunori ISHIKAWA, Akira ...1980 年 88 巻 3 号 p. 905-908
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーHepatic triglyceride lipase (H-TGL) obtained from postheparin plasma is first stimulated and then progressively inhibited by addition of an increasing amount of serum. To solve the mechanism of this modification, serum fractions isolated by ultracentrifugation were added to the assay mixture and their effects on H-TGL activity were determined. We demonstrated that the addition of the d=1.21 bottom fraction together with HDL almost fully reproduces the effect of the whole serum.抄録全体を表示PDF形式でダウンロード (235K) -
Role of Regulatory Light Chain of Myosin in Calcium Regulation of Muscle ContractionHiroshi SUZUKI, Kunihiko KONNO, Ken-ichi ARAI, Shizuo WATANABE1980 年 88 巻 3 号 p. 909-911
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーRemoval of the regulatory light chain subunit (EDTA light chain) of myosin from glycerinated fibers of scallop adductor striated muscle resulted in an immediate loss of calcium sensitivity of tension development and in a subsequent decrease in tension developed in the presence of calcium. It is suggested that removal of EDTA light chain results in a change in the myosin heavy-chain conformation which is probably responsible for the decrease in tension development.抄録全体を表示PDF形式でダウンロード (180K) -
Possible Involvement of Ca2+-Activated, Phospholipid-Dependent Protein Kinase in Platelet ActivationYasuhiro KAWAHARA, Yoshimi TAKAI, Ryoji MINAKUCHI, Kimihiko SANO, Yasu ...1980 年 88 巻 3 号 p. 913-916
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーCa2+-activated, phospholipid-dependent protein kinase recently found in rat brain (Takai, Y., Kishimoto, A., Iwasa, Y., Kawahara, Y., Mori, T., & Nishizuka, Y. (1979) J. Biol. Chem. 254, 3692-3695) is present in large quantities in human platelets. The activation of this enzyme appears to be initiated by unsaturated diacylglycerol and intimately related to phosphatidylinositol hydrolysis which is induced by thrombin. The enzyme is selectively and profoundly inhibited by several phospholipid-interacting compounds such as imipramine, verapamil, and tetracaine, which concomitantly inhibit aggregation and release reaction in parallel manners. It is suggestive that this protein kinase may be involved in the transmembrane control of intracellular events eventually leading to platelet activation.抄録全体を表示PDF形式でダウンロード (273K) -
Yoshiyuki KANAI, Hisae KAWAMITSU, Mieko TANAKA, Taijiro MATSUSHIMA, Ma ...1980 年 88 巻 3 号 p. 917-920
発行日: 1980/09/01
公開日: 2008/11/18
ジャーナル フリーA novel method for the purification of poly (ADP-ribose) was established. Calf thymus nuclei were incubated with NAD. After pronase digestion, DNA was isolated as a flocculent form by adding 1M NaCl and 2 volumes of ethanol. Acid-insoluble poly(ADP-ribose), which was synthesized during incubation, was quantitatively recovered in this DNA fraction. Poly (ADP-ribose) was purified as a single peak from a hydroxylapatite column after the nuclease treatment. Preparation of poly (ADP-ribose) thus obtained revealed the characteristics of pure poly (ADP-ribose), including a ratio of A280 to A260 of 0.24.抄録全体を表示PDF形式でダウンロード (245K)
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