巻号一覧
104 巻, 1 号
選択された号の論文の31件中1～31を表示しています
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Jun Hirabayashi, Ken-ichi Kasai1988 年 104 巻 1 号 p. 1-4
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe complete amino acid sequence of a β-galactoside-binding lectin from human placenta was determined at protein level. The lectin consists of 134 amino acids and its N-terminal alanine is blocked with acetate. The lectin shows about 50% similarity with chick 14K lectin, which was the first vertebrate β-galactoside-binding lectin completely sequenced. Only 14 residues proved to be different from those of rat lung lectin, the sole mammalian lectin of which the complete sequence has been reported.抄録全体を表示PDF形式でダウンロード (408K) -
Toru Tamiya, Toshiyuki Miyazaki, Hiroshi Ishikawa, Norio Iriguchi, Tak ...1988 年 104 巻 1 号 p. 5-8
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe water distribution in the pulvinus of Mimosa can be visualized by an NMR imaging technique. After stimulation of a Mimosa plant, water in the lower half of the main pulvinus disappeared, the water previously contained in this area seeming to be transferred to the upper half of the main pulvinus. Movement of the water in conjunction with Mimosa movement was visualized sequentially by a non-invasive NMR imaging procedure.抄録全体を表示PDF形式でダウンロード (1980K) -
Takao Ojima, Kiyoyoshi Nishita1988 年 104 巻 1 号 p. 9-11
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThree components of Akazara scallop (Chlamys nipponensis akazara) troponin were well separated from each other by a single-step chromatography on CM-Toyopearl, although they were hardly separated on DEAE-Sephadex A-25. Moreover, by means of this CM-chromatography, the troponin components of rabbit were also readily separated with high purities and in high yields. The components thus separated were readily reconstituted and the Ca2+ regulatory function was fully recovered.抄録全体を表示PDF形式でダウンロード (1186K) -
Michio Kubota, Bunzo Mikami, Yoshio Tsujisaka, Yuhei Morita1988 年 104 巻 1 号 p. 12-13
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーCyclodextrin glucanotransferase from Bacillus stearothermophilus TC-91 has been crystallized from an ammonium sulfate solution by the dialysis equilibrium method. The crystals belong to the orthorhombic system, space group P212121, with cell dimensions of a=125.5 Å, b=88.1 Å, and c=81.5 Å. The crystals appear to be suitable for X-ray structure analysis, diffracting to at least 2.1 Å and being resistant to radiation damage.抄録全体を表示PDF形式でダウンロード (728K) -
Kazuo Ohki1988 年 104 巻 1 号 p. 14-17
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーPhase transition characteristics of ternary mixtures of dipalmitoylphosphatidic acid, dipalmitoylphosphatidylcholine, and phosphatidylethanolamine (dilauroyl-, dimyri-stoyl-, or dipalmitoyl-phosphatidylethanolamine) were examined by differential scanning calorimetry at various concentrations of calcium ions. In the absence of calcium ion, these ternary mixtures showed a broad phase transition, which suggested a high miscibility of these components. Addition of a low concentration of calcium ions showed a tendency to induce separation of the transition into a major one and a small one. As the concentration of calcium ions increased, the separation became more distinct and the transition enthalpy of the major transition decreased. At a Ca2+/dipalmitoylphosphatidic acid ratio (mol/mol) of 1.5, the major transition became similar to the transition of dipalmitoylphosphatidyl-choline and the phosphatidylethanolamine binary mixture. On the other hand, in a binary mixture dipalmitoylphosphatidic acid and dipalmitoylphosphatidylcholine, the Ca2+-induced phase separation was distinct even at the lowest concentration of calcium ions used inthe present experiment. The results indicate that a high concentration of calcium ion is required for inducing complete phase separation of the transition event in the ternary mixture because of its high miscibility. It is suggested that the phase separationrevealed by spin-labeled phospholipid in ternary mixtures at a low Ca2+ concentration might be a phase separation in a local domain.抄録全体を表示PDF形式でダウンロード (548K) -
Takayuki Sato, Kaoru Omichi, Tokuji Ikenaka1988 年 104 巻 1 号 p. 18-21
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA new fluorogenic acceptor for sialyltransferase, 2-[(2-pyridyl)amino]ethyl O-β-D-galacto-pyranosyl-(1→4) -β-D-glucopyranoside, was prepared from lactose as a starting material. Sialyltransferase activity was assayed by incubation of the enzyme with the acceptor and CMP-N-acetylneuraminic acid, separation of the fluorogenic sialylated product from the enzymatic reaction mixture by HPLC, and measurement of the product. Compared to assays so far reported that use radioactive substrates, this assay is simple and rapid. This method was used to assay sialyltransferase activity in human serum.抄録全体を表示PDF形式でダウンロード (440K) -
Saori Takahashi, Akiko Irie, Yoshihiro Miyake1988 年 104 巻 1 号 p. 22-29
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe complete amino acid sequence of human urinary prokallikrein has been determined by amino acid analysis and sequence determination of peptide fragments obtained from chemical and enzymological cleavages of kallikrein and by comparison of the N-terminal sequence of prokallikrein with that of kallikrein, the active form. Prokallikrein was a single chain polypeptide which comprised 238 amino acid residues of kallikrein and 7 amino acid residues of the propeptide. The sequence, Asn-X-Thr (Ser), which is a common glycosylation site was found at positions 78-80, 84-86, and 141-143. Two trypsin-suscep-tible sites were identified. One is the Arg(-1)-Ile (1) bond and the other is the Arg (87)-Gln(88) bond. The sequence of human urinary kallikrein was identical with that of human pancreatic and kidney kallikreins (Fukushima, D. et al. (1985) Biochemistry 24, 8037-8043; Baker, A.R. & Shine, J. (1985) DNA 4, 445-459), which were predicted from the nucleotide sequences of cDNAs. The primary structure of human urinary kallikrein is homologous to those of the other animal kallikreins and kallikrein-related proteins. Key amino acid residues, His (41), Asp(96), and Ser(190), required for catalytic activity and Asp (184) required for kallikrein-type specificity are completely conserved. The results show that human urinary prokallikrein and kallikrein are of tissue type and they are excreted in urine without any modification.抄録全体を表示PDF形式でダウンロード (844K) -
Naoto Tonouchi, Naoki Oouchi, Nobukazu Kashima, Misako Kawai, Kazuo Na ...1988 年 104 巻 1 号 p. 30-34
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーBSF-2 (B cell stimulatory factor-2/IL-6) is a member of the lymphokine family and responsible for B cell differentiation. Expression plasmids of human BSF-2 cDNAwere constructed using a trp promotor/operator and a trpA terminator. In an extract of Escherichia coli HB101 holding “direct” expression plasmid pBSF-2D, activity of BSF-2 was detected, but overproduction was not observed. A “fused” expression system was therefore developed to prepare the recombinant protein. In this system, cDNA was expressed as a fused protein with human IL-2 N-terminal peptide. In the case of the fused BSF-2 expression plasmid, pBSF-2F, inclusion bodies were observed and overproduction of the protein occurred. As this fused protein had a Phe-Arg-Ala sequence at the junction of hIL-2 and BSF-2, it was possible to process mature BSF-2 from the fused BSF-2 by treatment with kallikrein and aminopeptidase P. From 1 liter of E. coli culture, 45 mg of mature BSF-2 was purified; it had a relative biological activity equal to that of natural BSF-2 purified from T cells.抄録全体を表示PDF形式でダウンロード (459K) -
Hiroshi Takami, Eisuke Furuya, Kunio Tagawa, Yoshiteru Seo, Masataka M ...1988 年 104 巻 1 号 p. 35-39
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe subcellular compartmentalization of adenosine 5'-triphosphate (ATP) in isolated perfused rat heart and its relation to energy depletion in ischemia were examined by 31P nuclear magnetic resonance (31P-NMR) spectroscopy and chemical analyses. The signal intensities of the β-phosphate of ATP and creatine phosphate in the 31P-NMR were standardized by the intracellular volume ratio measured with 23Na-NMR to determine the actual content of each. During aerobic perfusion the ATP content determined by NME (13.7±2.2 μmol/g dry weight) was significantly lower than that found by chemical analysis (22.4±0.7 μmol/g dry weight), while the creatine phosphate contents determined by the two methods were the same. During ischemia at 33°C, the signal of the β phosphate of ATP in the 31P-NMR spectrum decreased progressively, disappearing completely after 16 min. But at this time 5.7± 1.7 μmol/g dry weight of myocardial ATP was still detected by chemical analysis. These results indicated that there were two different compartments of intracellular ATP in the heart, only one of which is detectable by 31P-NMR spectroscopy. and that during ischemia the ATP that is detectable, which seems to be the free ATP in the cytosol, decreased more rapidly than the ATP in the other compartment.抄録全体を表示PDF形式でダウンロード (1300K) -
Yoshikazu Emi, Tsuneo Omura1988 年 104 巻 1 号 p. 40-43
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe effects of phenobarbital (PB), 3-methylcholanthrene (MC), and α-naphthoflavone (α-NF) on the synthesis of drug-inducible forms of cytochrome P-450, P-450(PB-1), and P-450(MC-1), and sex-specific forms of cytochrome P-450, P-450(M-1), and P-450(F-1), in male and female rats were studied. Whereas P-450(PB-1) and P-450(MC-1) in liver microsomes were markedly induced in both sexes by treatment with PB and MC, respec-tively, the contents of P-450(M-1) and P-450(F-1) were significantly decreased by the treatments. α-NF, which is not a P-450 inducer, did not change the contents of sex-specific forms of cytochrome P-450. The translatable mRNAs of the P-450s were also determined by using an in vitro translation system. The mRNAs coding for P-450(PB-1) and P-450(MC-1) were increased by drug administrations. On the other hand, the mRNAs coding for P-450(M-1) and P-450(F-1) were transiently decreased by the drugs, and then returned to the normal levels. The time courses of the induction of the drug-inducible P-450s and the repression of the sex-specific P-450s showed no close correlation. α-NF had no effect on the synthesis of P-450(M-1) and P-450(F-1). We also found that the synthesis of P-450(M-1) in the livers of untreated rats showed no diurnal variations.抄録全体を表示PDF形式でダウンロード (501K) -
Shigenobu Kimura, Jun Utsumi, Shojiro Yamazaki, Hirohiko Shimizu1988 年 104 巻 1 号 p. 44-47
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーDisulfide bond interchange has been pointed out as a considerable problem in preparing recombinant proteins from Escherichia coli cells. This has been reported in the system of reducing denaturation followed by a refolding process, where incorrectly folded molecules are sometimes produced. As the possibility of disulfide bond interchange may also arise in the cytoplasm of E. coli cells, the state of sulfhydryl groups of recombinant proteins obtained from a nonreducing and nondenaturing process should be examined. The state of sulfhydryl groups of E. coli-derived recombinant human interferonβ1, which had been purified under nonreducing and nondenaturing conditions, was examined by using the N-(7-dimethylamino-4-methylcoumarinyl)maleimide (DACM) labeling technique. Among the three cysteine residues in E. coli-derived human interferon-β1, the 17th cysteine was identified as being unpaired, as in the natural molecule. However, it was found that three isomers of the recombinant protein could be formed when the protein was denatured with 6 M guanidine hydrochloride. These three isomers were identified as having unpaired cysteine residues at positions 17, 31, and 141, respectively. These results indicate that disulfide bond interchange occurs in E. coli-derived recombinant human interferon-β1 under denaturing conditions in spite of the absence of a reducing agent.抄録全体を表示PDF形式でダウンロード (461K) -
Shoji Tajima, Taku Yamamura, Akira Yamamoto1988 年 104 巻 1 号 p. 48-52
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーWe have isolated and analyzed apolipoprotein E5 gene from a patient with hyperlipo-proteinemia. Apolipoprotein E5 is a variant of apolipoprotein E with two additional units of positive charge and smaller apparent molecular weight than apolipoprotein E3, which is the major isoform of apolipoprotein E. The heterozygous gene of apolipoprotein E5/3 from the patient was cloned into λ phage. The cloned apolipoprotein E genes were subcloned into a murine retrovirus shuttle vector and were expressed. One out of four clones expressed apolipoprotein E5. The analysis of the nucleotide sequence of the exons and exon-intron boundary regions has shown a G to A substitution in the 18th nucleotide from the 5'-end of the third exon. This single base substitution changes the amino acid residue Glu to Lys at the third position from the amino-terminus of the mature protein, and gives two additional units of positive charge to the molecule.抄録全体を表示PDF形式でダウンロード (2636K) -
Takeshi Yamamoto, Terutaka Tsuda, Yasuo Hamamori, Noriyuki Nishimura, ...1988 年 104 巻 1 号 p. 53-56
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーFibroblast growth factor (FGF) plus insulin induced DNA synthesis in and proliferation of NIH/3T3 cells. The protein kinase C-activating phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), inhibited both the DNA synthesis and cell proliferation induced by FGF plus insulin. The concentration of TPA required for 50% inhibition of the DNA synthesis was about 5 nM. Phorbol-12, 13-dibutyrate, another protein kinase C-activating phorbol ester, also inhibited the DNA synthesis but 4α-phorbol-12, 13-didecanoate, known to be inactive for this enzyme, was ineffective. DNA synthesis started at about 12 h after the addition of FGF plus insulin. The inhibitory action of TPA on the DNA synthesis was observed when it was added within 12h after the addition of FGF plus insulin. These results suggest that phorbol esters exhibit an antiproliferative action through protein kinase C activation in NIH/3T3 cells, and that this action of phorbol esters is due to inhibition of the progression from the late G1, to the S phase of the cell cycle.抄録全体を表示PDF形式でダウンロード (435K) -
Monica Sharma, Ugra Sen Singh1988 年 104 巻 1 号 p. 57-61
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーAngiotensin converting enzyme [EC 3.4.15.1] was shown to exist in two distinct forms in bovine seminal plasma. The higher molecular weight form of the enzyme (angiotensin convering enzyme I) was purified to homogeneity by Sephadex G-200 gel filtration, and DEAE-Sepharose, blue Sepharose, and concanavalin A-Sepharose column chromatography. Final recovery of the enzyme was 9.0. The molecular weight of the enzyme was estimated to be 8×105 by the gel filtration method. A value of 4.6×105 was obtained for the reduced and denatured enzyme by dodecylsulfate polyacrylamide gel electrophoresis. The Stokes' radius, diffusion coefficient, and intrinsic viscosity of the purified enzyme were determined to be 95Å, 2.3×10-7 cm2/s, and 6.76 ml/g. The enzyme had a specific activity of 105.12 μmol/min/mg protein for hippurylhistidylleucine. The Km value for hippurylhis-tidylleucine was found to be 20 mM. Studies with EDTA suggest that metal ions which are tightly bound are required for its activity. The enzyme was inhibited by some heavy metal ions but did not required sulfhydryl groups for its activity. Trypsin treatment of the urea-denatured enzyme produced a catalytically active fragment with an Mr of 30, 000. Chemical hydrolysis of the native enzyme did not produce any active fragment.抄録全体を表示PDF形式でダウンロード (598K) -
Takako Nishiya, Monidipa DasGupta, Yukihisa Okumura, Thomas Ming Swi C ...1988 年 104 巻 1 号 p. 62-65
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーMonosialogangliosides (GM) purified from bovine brain were incorporated into circular dichroism (CD)-active liposomes and the effects of GM on the membrane dynamics were studied by CD spectroscopy. In the presence of 7 mol% of GM, the phase transition temperature (Tc) of the membrane increased by ca. 10°C compared with the membrane without GM and characteristic CD spectra were observed for CD-active liposomes incorporating Gm at low temperature. Asialogangliosides had no effect on the CD spectra or Tc. We have also studied the role of Gm in reducing leakage of [3H] sucrose from liposomes composed of egg phosphatidylcholine, dipalmitoyl phosphatidic acid, cholesterol and α-tocopherol with a molar ratio of 4:1:5:0.1 in the presence of human plasma at 25°C. The half-life of [3H]-sucrose leakage was 173h for liposomes incorporating 7 mol% of GM. On the other hand, the half-lives for liposomes incorporating 7 mol% of asialogangliosides and liposomes without glycolipids were 45 and 42h, respectively. These results indicate that sialic acid on the membrane surface contributes to the increase of Tc, to the change of the aggregation state of phospholipids and to the stabilization of liposomes in plasma.抄録全体を表示PDF形式でダウンロード (529K) -
Francisco Javier Rodriguez-Berrocal, Maria Páez de la Cadena, J ...1988 年 104 巻 1 号 p. 66-71
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーβ-D-Galactosidase has been purified to apparent homogeneity from rabbit spleen. The purification steps involved ammonium sulphate precipitation, DEAE-cellulose, concanavalin A-Sepharose, Sephadex G-200, and Sepharose 4B-(ε-aminocaproy1)-2-deoxy-β-D-glucosylamine affinity chromatographies. In the DEAE-cellulose step, the β-D-galactosidase was separated into two molecular forms, designated I and II, with similar pH optimum, Km, substrate specificity, and sensitivity to substrate analogues and other substances. Form I was purified 1, 800-fold with a yield of about 2% of the total activity. This form is heat-labile, it has an acid optimal pH (4.0), an isoelectric point of 6.7 and a molecular weight of 75, 000 daltons. Form II has an optimal pH of 3.6 and three different pI values (5.3, 5.7, and 6.7) whose relative proportions can be modified by treatment with neuraminidase. Form II appeared to be a multimeric form (IIA) of about 600, 000 daltons at pH 4.0, which was reversibly dissociated to an oligomeric form (IIB) with an apparent molecular weight of 120, 000 at neutral pH values. Both IIA and IIB were purified separately and showed an acid pH optimum and an heterogeneous pI (from 4.6 to 7.2). The dissociation of IIA into IIB can be generated spontaneously, but is increased by the presence of urea in the elution buffer, suggesting that both are aggregates of a common subunit.抄録全体を表示PDF形式でダウンロード (1300K) -
Shuzo Ishidate, Issei Mabuchi1988 年 104 巻 1 号 p. 72-80
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA novel protein factor which reduces the low-shear viscosity of rabbit skeletal muscle actin was purified from a 0.6M KCl-extract of an insoluble fraction of sea urchin eggs by ammonium sulfate fractionation, gel filtration column chromatography, DNase I column chromatography, and hydroxylapatite column chromatography. This protein factor was shown to be a one-to-one complex of a 20, 000-molecular-weight protein and egg actin. This protein complex accelerated the initial rate of actin polymerization, but reduced the steady-state viscosity of F-actin. It inhibited at substoichiometric amounts the elongation of actin filaments on sonicated F-actin fragments and depolymerization of F-actin induced by dilution. In addition, it increased the critical concentration of actin for polymerization. All these effects of this protein complex on actin could be explained by the “capping the barbed end” of the actin filament by the complex. The 20, 000-molecular-weight protein which was separated from actin also possessed the barbed end-capping activities, but differed from the complex in that it did not accelerate the polymerization of actin.抄録全体を表示PDF形式でダウンロード (3060K) -
Hirokazu Ueda, Tadao Hashimoto, Eisuke Furuva, Kunio Tagawa, Kazuo Kit ...1988 年 104 巻 1 号 p. 81-86
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe changes in cerebral metabolism in mice in severe hypoxia were investigated by analyses of changes in the levels of energy metabolites and near-infrared spectro-photometric assessment of the states of hemoglobin and cytochrome oxidase. Under 4.4% O2, the contribution of anaerobic ATP production was at most about 20% of the demand. However, the cerebral ATP level was kept at the control level until about 1 min before death. Pentobarbital anesthesia, which reduced the cerebral rate of metabolism, prolonged the survival time, although anaerobic ATP production still did not support ATP demand. Under these conditions, deoxygenation of hemoglobin and reduction of cytochrome oxidase proceeded rapidly within 1 min. Hemoglobin reached the maximum state of deoxygenation in the middle phase of hypoxia, with no further change until death. However, cytochrome oxidase was reduced slowly with one phase of partial reoxidation due to increase of cere-bral blood volume, and reached the completely reduced state at death. From these results it was concluded that the aerobic ATP synthesis, which supplied more than 80% of the cerebral demand, decreased gradually because of limitation of oxygen supply, and that the failure of oxidative phosphorylation to meet demand triggered the decrease in the cellular ATP level that led to death.抄録全体を表示PDF形式でダウンロード (723K) -
Kiyoshi Ogura, Shizuo Handa1988 年 104 巻 1 号 p. 87-92
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーGanglioside GM1 (NeuAc), labeled at the C-3 position of sphingosine with tritium, was injected into C3H/He, C57BL/10, B10.AQR mice intraperitoneally. The incorporation and the distribution of the radioactivity in various organs were examined. The injected [3H]GM1 (NeuAc) was mainly incorporated in the liver and hydrolyzed sequentially. Sialic acid of ganglioside GM1 (NeuAc) and metabolites was converted to N-glycolyl type from N-acetyl type. An appreciable amount of the sphingosine moiety in the administered GM1 (NeuAc), moreover, was reutilized, being converted to sphingomyelin, and incorpo-rated into alkyl chain of the ether lipid in phosphatidylethanolamine. The distributions of radioactivity in the metabolites of GM1 (NeuAc) administered to the three strains of mice were different from each other. In other organs, GM1 (NeuAc) was incorporated and metabolized only slightly. The N-methylamide, at the carboxyl group of the sialic acid, of the labeled ganglioside GM1 (GM1 (NeuAc)-NMe) was injected into C3H/He mice. Most of the administered [3H] GM1 (NeuAc)-NMe was incorporated in the liver, and was metabolized to GM3 (NeuAc)-NMe, via GM2 (NeuAc)-NMe, within 24 h. GM3 (NeuAc)-NMe was the only radioactive compound in the subsequent 10 weeks, but disappeared from the liver gradu-ally. N-Methylamide-modified gangliosides were resistant to hydrolysis by mouse hepatic sialidase, to elongation by glycosyltransferase and to N-glycolylation at N-acetyl-neuraminic acid by monooxygenase.抄録全体を表示PDF形式でダウンロード (725K) -
Tadashi Yoshimoto, Nobuhiro Murayama, Takashi Honda, Hiroshi Tone, Dai ...1988 年 104 巻 1 号 p. 93-97
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe aminopeptidase P gene in Escherichia coli HB101 was cloned into the plasmid pBR322. Introduction of the hybrid plasmid, pAPP01, into the E. coli DH1 resulted in an 8-fold increase of aminopeptidase P activity as compared with that of the host. The enzyme was purified by series of chromatographies on DEAE-Sephadex, QAE-Sephadex, and hydroxy-apatite. The purified enzyme was homogeneous as judged by disc-gel and SDS-gel electro-phoreses. The enzyme was inhibited strongly by EDTA and slightly by p-chloromercuri-benzoate, but was not affected by diisopropyl phosphorofluoridate, E-64, or iodoacetic acid. The optimum pH of the enzyme was 8.5. The enzyme was stable at pH 8 to 9. After incubation for 30 min at pH 8.0, 50% remaining activity was observed at 50°C. The enzyme was activated 3-fold by the addition of 5 μM Mn2+. The molecular weight of the enzyme was estimated to be 50, 000 and 200, 000 by SDS-PAGE and gel filtration, respectively. The amino terminal amino acid was identified to be serine by Edman degradation, indicating that the enzyme is composed of a homo-tetramer. The enzyme hydrolyzed X-Pro bonds (X=amino acid) of peptides. These characteristics suggest that cloned aminopeptidase P is identical to APP-II reported by Yoshimoto et al. (Agric. Biol. Chem. 52(8), in press (1988)).抄録全体を表示PDF形式でダウンロード (2460K) -
Yuzuru Sato, Kenji Fujiwara1988 年 104 巻 1 号 p. 98-101
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーHepatic ornithine decarboxylase activity in rats increased 2 h after partial hepatectomy, showing two peaks at 4 and 10 h. When the rats received 1, 3-diaminopropane (DAP) from 0 to 4 h or from 6 to 10 h, this increase was suppressed at 6 or 12 h, respectively, whereas hepatic spermidine N1 -acetyltransferase activity was enhanced by DAP administration at 6 as well as 12 h, though the levels at 12 h were one-fifth of those at 6 h. An increase in hepatic DNA synthesis at 22 h did not occur in the rats given DAP from 6 to 10 h. It recovered after administration of putrescine, but not that of spermidine. In contrast, such an inhibition was not seen in the rats given DAP from 0 to 4 h; it occurred when quinacrine, a polyamine oxidase inhibitor, was concomitantly dosed, and disappeared with further addition of putrescine. Hepatic DNA synthesis changed in close association with hepatic putrescine content irrespective of spermidine and spermine contents in these rats. Putres-cine may be essential for liver regeneration after partial hepatectomy, and can be produced in sufficient quantity to support hepatic DNA synthesis by the compensatory route of spermidine acetylation and oxidation when ornithine decarboxylase activity is suppressed at an early stage.抄録全体を表示PDF形式でダウンロード (455K) -
Masayuki Takahashi, Hitoshi Sohma, Fumi Morita1988 年 104 巻 1 号 p. 102-107
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe ATP-induced difference UV-absorption spectrum of myosin isolated from the opaque portion of scallop smooth muscle (opaque myosin) was Ca2+ -sensitive at 40 mM KC1 and 1.5 M sucrose. On adding sucrose to 1.5 M, the turbidity of myosin decreased to 24% and the characteristic two forms of the difference spectrum, the ATP-form and ADP-form (Morita, F. (1967) J. Biol. Chem. 242, 4501-4506), were distinguishable. In the presence of Ca2+, the difference spectrum was the ATP-form first and then decayed into the ADP-form with the depletion of ATP. In the absence of Ca2+, however, only the ADP-form was observed. The ADP-form observed in the absence of Ca2+ returned to the ATP-form when the regulatory light chain-a (RLC-a), one of the regulatory light chains of opaque myosin, was phosphorylated. These results suggest that the main intermediate at the steady state of opaque myosin ATPase is converted depending on the concentration of Ca2+, from E_??_ in the presence of Ca2+ to EADP in the absence of Ca+2. It changes to E_??_ in the absence of Ca2+ on the phosphorylation of RLC-a. Consistent results were obtained by measuring the ATP-induced Trp-fluorescence increase of opaque myosin in the absence of sucrose. Since the opaque portion of scallop smooth muscle is known to be responsible for catch contraction (Ruegg, J.C. (1961) Proc. R. Soc. London Ser. B 154, 224-249), these findings lead us to suppose that the opaque myosin in vivo may stay in the E•ADP complex during the catch state. It changes to E_??_ by the phosphorylation of RLC-a, which may terminate the catch state.抄録全体を表示PDF形式でダウンロード (724K) -
Makoto Kawakami, Shosuke Takemura, Tadao Kondo, Takehiro Fukami, Toshi ...1988 年 104 巻 1 号 p. 108-111
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThere are two species of glycine tRNA, tRNAGly1 and tRNAGly2, in the posterior silk glands of Bombyx mori. The first positions of their anticodons are guanosine and an unknown nucleoside for tRNAGly1 and tRNAGly2, respectively. This new nucleoside was isolated and the chemical structure was analyzed by thin layer chromatography and by UV, 1H-NMR, field desorption mass, and ORD spectroscopic measurements. The structure characterized by physical methods was finally confirmed by synthesis to be 5-((S)-carboxy(hydroxy) methyl)uridine methyl ester.抄録全体を表示PDF形式でダウンロード (382K) -
Akihiko Moriyama, Makoto Nakanishi, Makoto Sasaki1988 年 104 巻 1 号 p. 112-117
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーProlyl endopeptidase [EC 3.4.21.26] was purified 4, 675-fold with a yield of 26.3% from porcine muscle. The purified enzyme was shown to be very similar to the liver enzyme with respect to its molecular weight (72, 000-74, 000), antigenicity, substrate specificity, and susceptibility to protease inhibitors. Among several bioactive peptides, angiotensins I, H, and III had the lowest Km of 0.6 to 3 μM with the lowest kcat of 0.19 to 0.85 s-1, while thyrotropin-releasing hormone had the highest Km of 98 μM with the highest kcat of 14.4s-1 Interestingly, mastoparan was hydrolyzed at alanyl bonds, but insulin was only slightly hydrolyzed and glucagon was not hydrolyzed although the latter two peptides contain prolyl and/or alanyl bonds. Muscle prolyl endopeptidase failed to hydrolyze proteins with high molecular weight such as albumin, immunoglobulin G, elastin, collagen, and muscle soluble and insoluble proteins. However, 8 of 14 peptides with molecular weights lower than 3, 000, which were isolated from muscle extract, were digested by this enzyme, and they were proved to contain prolyl and/or alanyl residues in their molecules. The data suggest that they are probable endogenous substrates for prolyl endopeptidase.抄録全体を表示PDF形式でダウンロード (2873K) -
Masahiro Uritani, Masazumi Miyazaki1988 年 104 巻 1 号 p. 118-126
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe stimulatory effect of peptide elongation factor 3 (EF-3), which is uniquely required for the yeast elongation cycle, on the step of binding of aminoacyl-tRNA (AA-tRNA) to ribosomes has been investigated in detail. Yeast EF-lα apparently functions in a stoichiometric manner in the binding reaction of AA-tRNA to the ribosomes. The addition of EF-3 and ATP to this binding system strikingly stimulated the binding reaction, and the stimulated reaction proceeded catalytically with respect to both EF-1α and EF-3, accompanied by ATP hydrolysis, indicating that EF-3 stimulated the AA-tRNA binding reaction by releasing EF-lα from the ribosomal complex, thus recycling it. This binding stimulation by EF-3 was in many respects distinct from that by EF-1βγ. The idea that EF-3 may participate in the regeneration of GTP from ATP and the formed GDP, as indicated by the findings that the addition of EF-3 along with ATP allowed the AA-tRNA binding and Phe polymerization reactions to proceed even in the presence of GDP in place of GTP, was not verified by the results of direct measurement of [32P]GTP formation from [γ-32P] ATP and GDP under various conditions. Examination of the stability of the bound AA-tRNA disclosed the different binding states of AA-tRNA on ribosomes between in the cases of the complexes formed with EF-1α alone, or factor-independently, and with EF-1α and EF-3. Furthermore, we found that whereas the EF-1α-promoted reaction allowed the binding of noncognate AA-tRNA to a certain extent, the EF-3-stimulated reaction strictly selected to bind only cognate AA-tRNA correctly pairing between codon and anticodon. Thus, we concluded that, for AA-tRNA binding to ribosomes, at first EF-1α carries AA-tRNA in the ternary complex with GTP to the ribosomal introducing site (I-site) with a little binding of noncognate AA-tRNA, and then EF-3 plays a key role in the strict selection of cognate AA-tRNA and in its transfer from the I- to the A-site, by changing its binding state, accompanied by ATP hydrolysis.抄録全体を表示PDF形式でダウンロード (1114K) -
Shigeru Kitayama, Osamu Matsumura, Susumu Masuda1988 年 104 巻 1 号 p. 127-130
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA protein which preferentially binds Z-form duplex DNA has been purified from the cells of Deinococcus radiodurans. The molecular weight of the protein was estimated to be approximately 68, 000 by gel filtration and SDS-polyacrylamide gel electrophoresis. Amino acid analysis of the protein indicates that it is not so basic since it contains a lower mole percent of lysine and higher mole percent of aspartic acid than those in histone-like DNA binding protein II (HU) of Escherichia coli. The first fifteen amino acid residues from the N-terminus have been also determined.抄録全体を表示PDF形式でダウンロード (2373K) -
Shinji Masuyoshi, Toyoji Okubo, Matsuhisa Inoue, Susumu Mitsuhashi1988 年 104 巻 1 号 p. 131-135
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーVibrio anguillarum strains were isolated from chloramphenicol-resistant bacteria in diseased fish. Plasmid Rms418, which confers chloramphenicol resistance, wastransferred from V. anguillarum GN11379 to Escherichia coli K12 by conjugation. The Rms418-encoded chloramphenicol acetyltransferase (CAT) [EC 2.3.1.99] was isolated and purified to homogeneity using affinity chromatography on immobilized p-amino-chloramphenicol or ATP. The general CAT could be adsorbed by a matrix with a chloramphenicol base ligand (Zaidenzaig, Y. & Shaw, W. V. (1976) FEES Lett. 62, 266-271), but the Rms418-encoded CAT was not bound under these conditions. The specific activity of the enzyme, when measured by the spectrophotometric assay, was 71.4 units/mg protein at 37°C. The molecular weight of the enzyme treated with SDS and 2-mercaptoethanol was shown to be approximately 22, 000. The molecular weight of the native enzyme, as determined by gel filtration, was approximately 69, 000, and the optimal pH was 7.8. The Km values for chloramphenicol and CoASAc were 34.5 and 150 μM, respectively. Enzyme activity was inhibited by HgCl2, p-chloromercuribenzoate (p-CMB), 5, 5'-dithiobis(2-nitrobenzoic acid) (DTNB), and ethylendiaminotetraacetic acid (EDTA). The half life at 53°C was approximately 100min.抄録全体を表示PDF形式でダウンロード (1612K) -
Norihide Shimizu, Kazuo Kobayashi, Koichiro Hayashi1988 年 104 巻 1 号 p. 136-140
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe optical absorption spectrum of bovine liver catalase was found to change on light irradiation in the presence of proflavin and EDTA in a deaerated solution. Uponaddition of CO to the photolyzed product, the spectrum changed to an another form, suggesting that the photolyzed product is the ferrous form of the enzyme and CO is bound to the ferrous enzyme. When O2 was introduced into the ferrous enzyme, the absorption spectrum returned to its original ferric state. An intermediate spectrum was obtained in this reaction at -20°C in 33% v/v ethylene glycol. Judged from the spectral characteristics of this compound, it is probably an oxyferrous enzyme. It was converted into ferric enzyme gradually when the sample was left at room temperature. The ferrous enzyme, which was generated by flash photolysis of the CO complex of the enzyme in an air-saturated buffer, reacted with O2 to form the oxyferrous enzyme with a second order rate constant of 9.2 × 103 M-1•s-1 at pH 8.6 and 20°C. The oxyferrous enzyme thus obtained autodecomposed into the ferric form with a rate constant of 0.1 s-1.抄録全体を表示PDF形式でダウンロード (609K) -
Hiromitsu Okabe, Shinji Yokoyama, Akira Yamamoto1988 年 104 巻 1 号 p. 141-148
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーIn order to investigate the effect of cholesteryl ester (CE) accumulation in plasma lipoprotein on its metabolism, change of the cholesterol (CHOL) microenvironment was studied by using a lipid microemulsion model system (J. Biol. Chem. 258, 10073-10082, 1983 and 260, 16375-16382, 1985) in the presence of CE and apolipoproteins. Solubility of CHOL in the triolein (TG) core of the emulsion was limited (0.4 weight percent), so that most of the CHOL in the emulsion was found to be associated with the phosphatidylcholine (PC) surface membrane. CE was associated almost exclusively with the TG core without any significant effect on the partitioning of cholesterol between the core and the surface. However, membrane-associated CHOL seems to be present in the TG core adjacent to the surface membrane in the microemulsion without CE, and it is likely to be shifted into the membrane by the presence of CE in the core according to the compositional analysis. Binding parameters of apolipoproteins (apo) A-I, A-II, C-III1, and E were not significantly different among the emulsions with and without CHOL and/or CE at CHOL/PC ratios up to 0.17 (w/w). Susceptibility of CHOL to cholesterol oxidase was observed as an enzymatic probe for CHOL microenvironment. In the absence of apolipoproteins, CHOL reacted similarly to the enzyme regardless of its shift by CE. When apolipoproteins bound to the emulsion containing only CHOL, the rate of CHOL oxidation was decreased by 40% with apoE but not with the others. In the presence of CE, it was decreased by 80% with apoA-I and E, and by 65 and 35% with apoC-III, and apoA-II, respectively. These results indicated that apolipoproteins modulate CHOL environment more potently when lipoprotein contains more CE and that this modulation is the strongest with apoE.抄録全体を表示PDF形式でダウンロード (1993K) -
Sachio Morimoto, Iwao Ohtsuki1988 年 104 巻 1 号 p. 149-154
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーTroponin C was removed almost completely from the porcine cardiac myofibrils by the same extraction procedure using CDTA as that previously reported for the rabbitskeletal myofibrils (Morimoto, S. & Ohtsuki, I. (1987) J. Biochem. 101, 291-301), and the effects of substitution of troponin C in cardiac myofibrils with rabbit skeletal troponin C or bovine brain calmodulin were examined. While the ATPase activity of intact cardiac myofibrils or cardiac troponin C-reconstituted cardiac myofibrils was activated at only a little higher concentration of Sr2+ than Ca2+, the skeletal troponin C-substituted cardiac myofibrils, as well as intact rabbit skeletal myofibrils, required more than 10 times higher concentration of Sr2+ than Ca2+ for activation of the myofibrillar ATPase activity. However, the concentrations of Ca2+ and Sr2+ required for the activation of the ATPase activity of the skeletal troponin C-substituted cardiac myofibrils were both about 5 times higher than those of intact skeletal myofibrils. The skeletal troponin C-substituted cardiac myofibrils, as well as intact skeletal myofibrils, also showed higher cooperativity in the Ca2+-activation of the ATPase activity than intact or cardiac troponin C-reconstituted cardiac myofibrils. The ATPase activity of calmodulin-substituted cardiac myofibrils was activated at a several times lower concentration of Ca2+ or Sr2+ than that of calmodulin-substituted skeletal myofibrils, while the ratios of the concentration of Sr2+ to Ca2+ required for activation were almost the same in both cases. The results indicate that, among the characteristics of divalent cation regulation in the contraction of skeletal and cardiac muscles, the higher sensitivity to Ca2+ relative to Sr2+ and the higher cooperativity in the divalent cation activation in skeletal muscle than in cardiac muscle are determined solely by the species of troponin C, but the sensitivities to the divalent cations in the contraction of skeletal and cardiac muscle are determined through the interactions between troponin C and other troponin components.抄録全体を表示PDF形式でダウンロード (1795K) -
Masayasu Inoue, Irwin M. Arias1988 年 104 巻 1 号 p. 155-158
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーTo elucidate the mechanism of taurine transport across the hepatic plasma membranes, rat liver sinusoidal plasma membrane vesicles were isolated and the transport process was analyzed. In the presence of a sodium gradient across the membranes (vesicle inside < vesicle outside), an overshooting uptake of taurine occurred. In the presence ofother ion gradients (K+, Li+, and choline+), taurine uptake was very small and no such overshoot was observed. Sodium-dependent uptake of taurine occurred into an osmotically active intravesicular space. Taurine uptake was stimulated by preloading vesicles with unlabeled taurine (transstimulation) in the presence of NaCl, but not in the presence of KCl. Sodium-dependent transport followed saturation kinetics with respect to taurine concentration; double-reciprocal plots of uptake versus taurine concentration gave a straight line from which an apparent Km value of 0.38mM and Vmax of 0.27nmol/20s×mg of protein were obtained. Valinomycin-induced K+-diffusion potential failed to enhance the rate of taurine uptake, suggesting that taurine transport does not depend on membrane potential. Taurine transport was inhibited by structurally related ω-amino acids, such as β-alanine and γ-aminobutyric acid, but not by glycine, ε-aminocaproic acid, or other α-amino acids, such as L-alanine. These results suggest that Na+ -dependent uptake of taurine might occur across the hepatic sinusoidal plasma membranes via a transport system that is specific for ω-amino acids having 2-3 carbon chain length.抄録全体を表示PDF形式でダウンロード (459K)
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