巻号一覧
104 巻, 6 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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Sumihiro Hase, Shun-ichiro Kawabata, Hitoshi Nishimura, Hiroyuki Takey ...1988 年 104 巻 6 号 p. 867-868
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA new trisaccharide sugar chain was identified in bovine blood coagulation factors VII andIX. A pentapeptide isolated from factor VII contained Ser-52, which could not be identified with a gas-phase sequencer, suggesting an unknown substituent on the serine residue (Takeya, H. et al. (1988) J. Biol. Chem., in press). The same results were obtained for a pentapeptide containing Ser-53 of factor IX. Component sugar analysis revealed that the peptide contained 1 mol of glucose and 2 mol of xylose. This sugar component was also confirmed by high-resolution fast atom bombardment mass spectrometric analysis of the pentapeptide. The trisaccharide was released from the peptides by means of β-elimination reaction and its reducing end was coupled with 2-aminopyridine. The fluorescent pyridylamino (PA-) derivative of the trisaccharide was purified by gel-filtration and reversed-phase HPLC. The sugar composition of the PA-trisaccharide was found to be 2 mol of xylose and 1 mol of PA-glucose. These results indicate the existence of a (Xyl2)G1c-Ser structure in factors VII and IX.抄録全体を表示PDF形式でダウンロード (217K) -
Hideki Tachibana, Yoshifumi Inoue, Takeharu Kanehisa, Yasuo Fukami1988 年 104 巻 6 号 p. 869-872
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーWe found local sequence-similarity between the non-catalytic region of the Rous sarcoma virus oncogene product, p60v-src, and the core region of cytoskeletal keratin through an extensive similarity search of segments of proteins. The segments showing similarity in p60v-src were in the region that is important for morphological transformation, and corresponded to segments with unique structural features predicted for intermediate filament proteins. We suggest that cellular components related with intermediate filament proteins or the sequence shared by the two proteins may be involved in the regulation of the kinase activity or substrate specificity of p60v-src.抄録全体を表示PDF形式でダウンロード (475K) -
Sachio Morimoto, Takashi Fujiwara, Iwao Ohtsuki1988 年 104 巻 6 号 p. 873-874
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーSingle fibers from glycerinated rabbit psoas muscle were treated with a solution containing CDTA, a strong chelator of metal ions. The CDTA-treated fibers lost all of the troponin C and showed no Ca2+-activated tension development. The addition of troponin C restored the Ca2+-activated tension of CDTA-treated fibers. The tension-pCa relationship in the case of the CDTA-treated fibers reconstituted with troponin C was almost the same as that in the case of the same fibers before the CDTA treatment. These results are consistent with those of the previous study on the Ca2+-activated ATPase of CDTA-treated rabbit skeletal myofibrils (Morimoto, S. & Ohtsuki, I. (1987) J. Biochem. 101, 291-301).抄録全体を表示PDF形式でダウンロード (986K) -
Tatsuya Moriyama, Hitoshi Takamura, Hiroshi Narita, Ken-ichi Tanaka, T ...1988 年 104 巻 6 号 p. 875-877
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe Ca2+ channel blocker, nifedipine, a dihydropyridine derivative, inhibited the Ca2+ influx and release from internal stores caused by collagen or a low concentration of the thromboxane A2 (TXA2) analogue, 9, 11-epithio-11, 12-methano-TXA2 (STA2) (10nM), but did not inhibit those caused by thrombin or a high concentration of STA2 (100nM). These results indicate the presence of two distinct, dihydropyridine-sensitive and insensitive, Ca2+ channels dependent on the concentrations and classes of agonists in human platelets.抄録全体を表示PDF形式でダウンロード (264K) -
Mitsuhiko Sugimoto, Toshiyuki Miyata, Shun-ichiro Kawabata, Akira Yosh ...1988 年 104 巻 6 号 p. 878-880
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーFactor IX Niigata is a mutant factor IX responsible for the moderately severe hemophilia B in a patient who has a normal level of factor IX antigen with reduced clotting activity (1-4% of normal). We reported previously that the purified mutant protein could be converted to the factor IXaβ form by factor XIa/Ca2+ at a rate similar to that in the case of normal factor IX, but the resulting mutant factor IXaβ could not activate factor X in the presence of factor VIII, Ca2+, and phospholipids (Yoshioka, A. et al. (1986) Thromb. Res. 42, 595-604). In the present study, we analyzed factor IX Niigata at the structural level to elucidate the molecular abnormality responsible for the loss of clotting activity. Amino acid sequence analysis of a peptide obtained on lysyl endopeptidase digestion, coupled with subsequent SP-V8 digestion, demonstrated that the alanine at position 390 was substituted by valine in the catalytic domain of the factor IX Niigata molecule.抄録全体を表示PDF形式でダウンロード (307K) -
Kaoru Omichi, Tokuji Ikenaka1988 年 104 巻 6 号 p. 881-883
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe course of the action of human salivary α-amylase (HSA) on a substrate was examined taking advantage of its transglycosylation action. IG5Φ(IG-G-G-G-G-Φ), IG4Φ (IG-G-G-G-Φ), and GIG4Φ (G-IG-G-G-G-Φ) were used as the substrates and p-nitrophenyl a-glucoside (GP, G-P) as the acceptor. HSA hydrolyzes IG5Φ, IG4Φ, and GIG4Φto IG3 (IG-G-G) and G2Φ (G-G-Φ), to IG3 and GΦ (G-Φ), and to GIG3 (G-IG-G-G) and GΦ, respectively. In the presence of GP, a part of the glycon residues, IG3 and GIG3, were transferred to the acceptor to give IG4P (IG-G-G-G-P) and GIG4P (G-IG-G-G-G-P), respectively. Whenever the enzyme attacks the substrate, GΦ or G2Φ is liberated in both transglycosylation and hydrolysis. The extent of transglycosylation can be, therefore, estimated from the molar ratio of the transfer product to the liberated aglycon, GΦ or G2Φ. HPLC analysis of the reaction mixtures revealed that the value of IG4P/GΦ in the digest of IG4.Φ was nearly equal to that of GIG4P/ GΦ in the digest of GIG4Φ and these values were ten times larger than that of IG4P/GΦ in the digest of IG5Φ. These data suggested that GΦ residue would fall away from aglycon binding site more rapidly than G2 Φ residue after the cleavage of the α-1, 4-glycosidic linkage to offer GP more chance to attack to the activated glycon and also indicated that the space of the glycon binding site corresponds to three glucose residues.抄録全体を表示PDF形式でダウンロード (382K) -
Makoto Murakami, Tetsuyuki Kobayashi, Masato Umeda, Ichiro Kudo, Keizo ...1988 年 104 巻 6 号 p. 884-888
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーMonoclonal antibodies which bind specifically to rat platelet phospholipase A2 have been raised. None of them bound to exocrine phospholipase A2 derived from pancreas or snake venom. All antibodies recognized the conformational structure of rat platelet phospholipase A2 supported by intramolecular disulfide bonds, since the reactivity between the antibodies and the enzyme was lost in the presence of 2-mercaptoethanol. One of them, designed MB5.2, inhibited the activity of the platelet phospholipase A2 in a dose-dependent manner. A kinetic study revealed that antibody MB5.2 apparently competed with the substrate for the active site of the enzyme. The other antibodies, designed MD7.1 and ME6.1, inhibited the binding of the enzyme to heparin. The distribution of phospholipases A2 bearing a similar determinant to rat platelet phospholipase A2 was investigated by immunoprecipitation of the enzyme activity or by an immunoblot technique. Among rat tissues, cross-reactivity was observed with phospholipases A2 from spleen, lung, and bone marrow. Extracellular phospholipase A2 detected in the peritoneal cavity of casein-treated rat was also recognized by these antibodies. Furthermore, antibody MD7.1 cross-reacted with rabbit and guinea pig platelet phospholipases A2.抄録全体を表示PDF形式でダウンロード (2807K) -
Hitoshi Sohma, Hirohiko Sasada, Kaoru Inoue, Fumi Morita1988 年 104 巻 6 号 p. 889-893
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーRegulatory light chain-a myosin kinase (aMK), which phosphorylates one of the myosin regulatory light chains, RLC-a, contained in the catch muscle of scallop, was also found to phosphorylate heavy chains of scallop myosin. After incubation of myosin isolated from the opaque portion of scallop smooth muscle (opaque myosin) with aMK in the presence of [γ-32P] ATP, about 2 mol of 32P was incorporated per mol of the myosin. The radioactivity was mostly found in the heavy chain at 0.26 M KC1. The pH-activity curve and MgCl2 requirement for the heavy chain phosphorylation were similar to those for RLC-a phosphorylation. In contrast, the dependency of activity on KC1 concentration was different from that for RLC-a. The heavy chain phosphorylation activity decreased with increase in KC1 concentration up to 0.06M, and then increased at concentrations over 0.06 M to a maximum at around 0.26 M KC1. This complicated profile probably reflects the solubility of myosin, and the phosphorylation site may be located in the rod portion insoluble at low KC1 concentrations. Phosphorylation of heavy chain did not change the solubility of the opaque myosin molecule at all. The acto-opaque myosin ATPase activity in the presence of Ca2+ was found to be decreased to less than one-fourth by the heavy chain phosphorylation.抄録全体を表示PDF形式でダウンロード (548K) -
Takeshi Hikiji, Keiji Miura, Kazuhiro Kiyono, Isao Shibuya, Akinori Oh ...1988 年 104 巻 6 号 p. 894-900
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA Saccharomyces cerevisiae mutant that lacked phosphatidylserine synthase [EC 2.7.8.8] (CDP-1, 2-diacyl-sn-glycerol: L-serine O-phosphatidyltransferase) completely was constructed by disrupting its structural gene, CHO1. Over two-thirds of its coding region, from the starting to the 200th codon, was replaced with a LEU2 DNA fragment. This new cho1 mutant showed no detectable synthesis of phosphatidylserine but grew slowly in a medium that contained either ethanolamine or choline. These results indicate that phosphatidylserine synthase and most probably phosphatidylserine are dispensable in S. cerevisiae but necessary for its optimal growth. Additional supplementation with myo-inositol raised the cellular content of phosphatidylinositol and improved the growth of the mutant, suggesting the importance of the negative charges of the membrane surface. The CHO1-disrupted mutant, when grown on choline, accumulated phosphatidylethanolamine to a significant level even after extensive dilution of the initial culture. It segregated prototrophic revertants that could synthesize phosphatidylethanolamine without recovery of phosphatidylserine synthesis. These results imply the presence of a route(s) for the formation of ethanolamine or its phosphorylated derivative in S. cerevisiae.抄録全体を表示PDF形式でダウンロード (1769K) -
Akira Takeda, Makoto Kanoh, Takashi Shimazu, Nozomu Takeuchi1988 年 104 巻 6 号 p. 901-907
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーMonoclonal antibodies (2-3E2, 6-3G11, and 7-3H6) against gap junction plaques purified from rat liver were prepared and characterized. Immunoblot analysis of liver gap junctions revealed that all three antibodies reacted with the 27-kDa protein, but not with the 22-kDa one. The 2-3E2 and 6-3G11 antibodies both reacted with the 27-kDa protein in gap junctions purified from livers of the rat, mouse, rabbit, and guinea pig; the 7-3H6 antibody, however, failed to react with the 27-kDa protein from guinea pig liver. The 7-3H6 antibody reacted strongly with the 24- to 26-kDa degradation products of the 27-kDa protein. Indirect immunofluorescence showed that the 6-3G11 and 7-3H6 antibodies both gave the same specific fluorescence labeling on rat liver cryosections, suggesting that these two antibodies recognized the cytoplasmic sites of the 27-kDa protein. Immunoblot analysis of proteasedigested fragments from the 27-kDa protein revealed that the 7-3H6 antibody reacted with the 24- and 17-kDa fragments (including portions of the carboxyl-terminal domain of the 27-kDa protein) produced with endoproteinases Arg-C and Lys-C, respectively. Immunoblot analysis of CNBr fragments of the 27-kDa protein revealed that all three antibodies reacted with the 10-kDa fragment, which is thought to be the carboxyl-terminal domain of the 27-kDa protein. These results demonstrate that three monoclonal antibodies recognize different epitopes of the cytoplasmic sites (probably the carboxyl-terminal domain) of the 27-kDa liver gap junction protein.抄録全体を表示PDF形式でダウンロード (5708K) -
Kazuhiro Mitsui, Takuzo Nakagawa, Kunio Tsurugi1988 年 104 巻 6 号 p. 908-911
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA small but distinct amount of yeast acidic ribosomal proteins Al/A2 was detected in cytosol by immunoblotting on a two-dimensional gel electrophoretogram, while 38 kDa acidic protein A0 was not detected. The free forms of Al/A2 in the cytosol were eluted in gel filtration at the molecular mass of about 30 kDa under non-denaturation conditions, suggesting that they exist as a dimer or timer without association with A0. The amount of free Al/A2 was determined by immunoblotting to be 0.3% of the ribosome-bound Al/A2 in yeast. The time course of incorporation of radioactive amino acid showed that the cytosolic free Al/A2 are labeled more rapidly with high specific radioactivity than the ribosome-bound Al/A2. This result suggested that some of the cytosolic Al/A2, if not all, are newly-synthesized proteins which are ready for incorporation into cytoplasmic ribosomes.抄録全体を表示PDF形式でダウンロード (2921K) -
Masayuki Komori, Takanori Hashizume, Hiroaki Ohi, Toshiaki Miura, Mits ...1988 年 104 巻 6 号 p. 912-916
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThree forms of cytochrome P-450, designated as P-450-HM1, P-450-HM2, and P-450-HM3, were isolated from human liver microsomes using high-performance liquid chromatogra-phy (HPLC) techniques. Each purified preparation showed a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). From the results of SDS-PAGE, the molecular weights of P-450-HM1, P-450-HM2, and P-450-HM3 were estimated to be 51, 000, 54, 000, and 52, 000, respectively. The oxidized absolute spectra of these three forms of cytochrome P-450 showed Soret absorption peaks at around 417 nm, indicating that these forms were in the low spin state. In a reconstituted system, P-450-HM1 showed the highest catalytic activities of nifedipine and (S)-or (R)-nilvadipine oxidases. The same form showed higher activities of testosterone 6β-hydroxylase and progesterone 6β-and 16α-hydroxylases. P-450-HM2 showed high N-demethylase activities for benz-phetamine and aminopyrine, and also showed the highest activity of testosterone 16α-hydroxylase among the three forms, while it did not show detectable activities of testosterone 6β-hydroxylase and progesterone 6β-and 16α-hydroxylases. Anti-P-450-HM1 immunoglobulin G (IgG), but not anti-P-450-HM2 IgG, inhibited the activities of testosterone 6β-hydroxylase and nifedipine and nilvadipine oxidases in human liver microsomes. Anti-P-450-HM1 IgG was also inhibitory against progesterone 6β-and 16α-hydroxylases. Amino-terminal sequences of P-450-HM1, P-450-HM2, and P-450-HM3 were homologous to those of P-450NF, and P-450MP, and P-450 HFLa, respectively, though dissimilarities in the nature of the purified forms from the reported data were noted.抄録全体を表示PDF形式でダウンロード (1632K) -
Yoshihiro Sawa, Hideo Ochiai, Kazushi Yoshida, Katsuyuki Tanizawa, Hid ...1988 年 104 巻 6 号 p. 917-923
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーGlutamine synthetase has been purified to homogeneity from cell extracts of a non-N2-fixing filamentous cyanobacterium, Phormidium lapideum. The subunit molecular weight of the enzyme was determined as about 59, 000 by sodium dodecyl sulfate gel electrophoresis. Electron micrographs of the Phormidium enzyme revealed a two-layered structure of regular hexagons (12 subunits per molecule), which markedly resembles the three-dimensional polypeptide backbone structure of the Salmonella typhimurium glutamine synthetase established by X-ray crystallography (Almassy, Janson, Hamlin, Xuong, & Eisenberg (1986) Nature 323, 304-309). The N-terminal amino acid sequence of the Phormidium enzyme shows very high similarity with that of the enzyme from an N2-fixing cyanobacterium, Anabaena 7120; 18 residues are common in 23 residues compared. Strong immunocross-reactions between the antibody against the purified Phormidium glutamine synthetase and other cyanobacterial enzymes except the Anacystis enzyme were observed. The apparent Michaelis constants for NH3, L-glutamate, and ATP were determined to be 0.29, 7.4, and 1.7 mM, respectively. Divalent metal ions such as Mg2+ and Mn2+ activated the enzyme in the biosynthetic reaction, whereas various amino acids and glutamate analogs strongly inhibited the enzyme.抄録全体を表示PDF形式でダウンロード (3333K) -
Manabu Sugimoto, Tadao Oikawa, Nobuyoshi Esaki, Hidehiko Tanaka, Kenji ...1988 年 104 巻 6 号 p. 924-926
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe gene coding for the Neurospora crassa copper metallothionein (MT) was synthesized and inserted in the lacZ' gene of pUC18 plasmid to give the same translational reading frame as the latter gene. The MT-β-galactosidase fused gene was expressed in Escherichia coli to produce a fused protein in which the amino and carboxy termini of MT are linked to the β-galactosidase through methionine residues. An MT derivative containing an extra homoserine residue at the carboxy terminus was prepared by cyanogen bromide cleavage of the fused protein followed by a reverse-phase HPLC separation. The spectral features of the MT derivative and its copper complex were similar to those of the corresponding native MTs.抄録全体を表示PDF形式でダウンロード (1680K) -
Yasufumi Minami, Yasufumi Emori, Shinobu Imajoh-Ohmi, Hiroshi Kawasaki ...1988 年 104 巻 6 号 p. 927-933
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーA mutant of the small subunit of rabbit calcium-dependent protease lacking the amino-terminal one-fourth produced in Escherichia coli could associate with the native large subunit to exert protease activity. Deletion of a few carboxyl-terminal residues of this variant small subunit caused a significant decrease in the protease activity after reconstitu-tion with the native large subunit. Loss of the fourth EF hand loop region by further truncation of the variant small subunit made interaction with the large subunit impossible. The calcium binding assay revealed that the fourth EF hand structure of the rabbit small subunit, which has been previously demonstrated to possess two calcium-binding sites, can bind calcium ions. Furthermore it was established by site-directed mutagenesis that the first EF hand structure, in addition to the fourth one, is capable of binding calcium ions. Replacement of amino acids in the EF hand structure affected interaction with the native large subunit or the calcium sensitivity of the reconstituted product. These findings indicate that the EF hand structure-domain of the small subunit is essential for the full protease activity.抄録全体を表示PDF形式でダウンロード (3873K) -
Eikichi Hashimoto, Keiko Mizuta, Youichirou Sakanoue, Hirohei Yamamura1988 年 104 巻 6 号 p. 934-938
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーProtein kinase C, reversibly bound to rat liver plasma membrane through Ca2+, was activated by endogenous trypsin-like protease in an ionic strength-dependent manner. In an attempt to understand the reaction mechanism, the EGTA-extracted protein kinase C and the trypsin-like protease (Tanaka, K. et al. (1986) J. Biol. Chem. 261, 2610-2615) were separately purified from plasma membrane. In the reaction system using these purified enzymes, increasing the ionic strength with NaC1 (140-210 mM) effectively enhanced the proteolytic activation of the protein kinase C in the presence of Ca2+ and phospholipid. These results suggest that ionic strength is an important factor for the proteolytic activation of membrane-bound rat liver protein kinase C.抄録全体を表示PDF形式でダウンロード (526K) -
Hideaki Watanabe, Hideo Katoh, Masami Ishii, Yuko Komoda, Akihiro Sand ...1988 年 104 巻 6 号 p. 939-945
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe primary structure of a pyrimidine base-specific ribonuclease from bovine brain wasdetermined. The sequence determinedisKESAAAKFRRQHMDSGSSSSSNPNYCNQMM KRRRMTHGRCKPVNTFVHESLDDVKAVCSQKNITCKNGHPNCYQSKSTMSITDCGSSKYPNCAYKTSQKQKYITVACEGNPYVPVHFDGAVLLPASPVPSLPPPIIRL.Althoughthe sequence homology of this RNase with bovine pancreatic RNase A is 78.2%, it consists of 140 amino acid residues, and it is 16 amino acid residues longer than RNase A at the carboxylterminal. In addition to an N-glycosylated long carbohydrate chain, the bovine brain RNase has two short O-glycosylated carbohydrate chains at the 129th and the 133rd serine residues. The additional C-terminal tail of the bovine brain RNase has a unique composi-tion: 6 proline, 5 hydrophobic amino acids, and two basic amino acids, arginine and histidine.抄録全体を表示PDF形式でダウンロード (1711K) -
Shigeo Nakajo, Yutaka Masuda, Kazuyasu Nakaya, Yasuharu Nakamura1988 年 104 巻 6 号 p. 946-951
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーCalmodulin is specifically phosphorylated by casein kinase 2 (CK 2), but not by casein kinase 1, A kinase, or C kinase. In the present report, the stoichiometry of thephosphorylation of calmodulin by CK 2 in the presence and absence of polylysine and its phosphorylation sites were examined. In the absence of polylysine, the radioactive phosphate incorporated into calmodulin by CK 2 was only 0.01 mol/mol and the phosphorylation occurred at Ser-101. In the presence of polylysine, 1.2mol of radioactive phosphate was incorporated into 1 mol of calmodulin. In this case, Thr-79 in addition to Ser-101 was phosphorylated, but Ser-81 was not. The sequence around the phosphorylated Thr is Asp-Thr (P) -Asp-Ser-Glu-Glu-Glu-.抄録全体を表示PDF形式でダウンロード (641K) -
Kana Goto, Akio Saito, Sumi Nagase, Hyogo Sinohara1988 年 104 巻 6 号 p. 952-955
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーIn healthy Nagase analbuminemic rats (NAR), the highest degree of relative increase in serum protein concentration was found for α-2-macroglobulin, the most prominent acute phase protein in rats. Its levels were about 30- and 60-fold higher in males and females, respectively, than those in the control Sprague-Dawley (SD) rats. In terms of absolute concentration, however, α-l-inhibitor 3 (also called α-X-protein or murinoglobulin) showed the most conspicuous change, its levels being higher by about 7 mg/ml than those in SD. When the acute phase reaction was induced by subcutaneous injection of turpentine, the levels of α-1- and α-2-macroglobulins, α-1-cysteine proteinase inhibitor, α-1- antiproteinase, and α-1-inhibitor 3 in NAR changed in essentially the same way as in SD: α-l-inhibitor 3 decreased markedly while the rest increased further. These results suggest that mechanisms responsible for the elevation of serum globulins in healthy NAR are not directly related to those involved in the acute phase response. On the other hand, the antithrombin III levels in healthy NAR were about twice the control values and changed little during the inflammation. In contrast, this protein in SD doubled during the acute phase, its maximal levels being close to those in healthy or inflamed NAR. This suggests that the antithrombin III level in healthy NAR is regulated by a mechanism similar to that in SD maximally reacting to the acute phase stress. Thus, the present results suggest that in healthy NAR, there is no common mechanism giving rise to the elevation of individual globulins, and that the mechanism underlying the acute phase response may be operative, at least to some extent, for a few proteins, but not for most proteins.抄録全体を表示PDF形式でダウンロード (475K) -
Miho Suzuki, Hiroshi Akanuma, Yasuo Akanuma1988 年 104 巻 6 号 p. 956-959
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe transport of 1, 5-anhydro-D-glucitol (AG) across plasma membranes wasinvestigated in rat hepatoma cells, Reuber H-35. The AG uptake by the cells showed a concentration gradient dependency: the uptake was saturated within 40 s, which was less than one-third of the saturation time for 2-deoxy-D-glucose (DG) uptake. Furthermore, the Km value of the transport system for AG was higher than 100 mM. Though AG has a pyranoid structure resembling that of glucose, AG did not compete for cellular uptake with DG, D-glucose or 3-0-methyl-p-glucose, which are taken into cells through the glucose transporters. Conversely, the DG transport was not inhibited by AG at concentrations up to 50 mM. AG transport was hardly inhibited by 100 μM cytochalasin B, which strongly inhibits glucose transporters. In contrast, the AG transport was inhibited by 100 μM phloretin much more strongly than the DG transport when cells were preincubated with the inhibitor; the inhibition constant was 28.0 μM. The AG transport was not inhibited by 100 μM phloridzin, while the DG uptake was slightly inhibited by phloridzin. On the basis of these observa-tions we propose that the AG uptake into rat hepatoma cells is mediated by a carrier distinct from glucose transporters.抄録全体を表示PDF形式でダウンロード (526K) -
Harumoto Yamada, Ross W. Stephens, Tomoyuki Nakagawa, David McNicol1988 年 104 巻 6 号 p. 960-967
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーSerum-free culture medium collected from primary monolayer cultures of human articular chondrocytes was found to inhibit human urokinase [EC 3.4.21.31] activity. Although chondrocyte culture medium contained a small amount of endothelial-type plasminogen activator inhibitor which could be demonstrated by reverse fibrin autography, most of the urokinase inhibitory activity of chondrocyte culture medium was shown to be due to a different molecule from endothelial-type inhibitor, since it did not react with a specific antibody to this type of inhibitor. The dominant urokinase inhibitor in chondrocyte culture medium was partially purified by concanavalin A-Sepharose affinity chromatography. The partially purified inhibitor inhibited high-Mr urokinase more effectively than low-Mr urokinase, but no obvious inhibition was detected against tissue-type plasminogen activator, plasmin, trypsin, and thrombin. The inhibitor had an apparent Mr of 43, 000 on sodium dodecyl sulfate polyacrylamide gel electrophoresis, and it was unstable to sodium dodecyl sulfate, acid, and heat treatments. Inhibition of urokinase by the inhibitor was accompanied with the formation of a sodium dodecyl sulfate-stable high-Mr complex between them. Inhibition and complex formation required the active site of urokinase. The partially purified inhibitor was thought to be immunologically different from the known classes of plasminogen activator inhibitors, including endothelial-type inhibitor, macro-phage/monocyte inhibitor, and protease nexin, since it did not react with specific anti-bodies to these inhibitors.抄録全体を表示PDF形式でダウンロード (4440K) -
Shinzo Nishi, Yoshikazu Koyama, Takashi Sakamoto, Mitsuhiko Soda, Clau ...1988 年 104 巻 6 号 p. 968-972
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーRat α-fetoprotein (AFP) cDNA spanning the complete coding region was cloned and expressed in Escherichia coli as well as in yeast, Saccharomyces cerevisiae. The recom-binant AFPs (rAFPs) were purified and characterized. The molecular weights determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis were 65, 000 for E. coli rAFP and 69, 000 for yeast rAFP. Amino acid and N-terminal sequence analyses indicated that yeast cells produced mature AFP by processing the signal peptide properly but E. coli rAFP lacked the N-terminal 53 amino acid residues of preAFP. The yeast rAFP was found to be indistinguishable from authentic AFP in the Ouchterlony immunodiffusion test, radioimmunoassay and estradiol-binding assay while E. coli rAFP was less reactive in these tests. These observations indicated that the rAFP expressed in yeast emulated the properties of authentic AFP.抄録全体を表示PDF形式でダウンロード (1829K) -
Yoshio Hirabayashi, Mitsue Hirota, Makoto Matsumoto, Hideaki Tanaka, K ...1988 年 104 巻 6 号 p. 973-979
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーWe have established many mouse monoclonal antibodies detecting developmentally regulated antigens in chicken embryonic neural tissues of the otic vesicles and neural tube by immunizing mice with the membrane fraction of the neural tube and somite prepared from 3-d chick embryos. Among them, three monoclonal antibodies (MAbs) M6703, M6704, and M7103 were shown to react with the gangliosides isolated from chicken embryonic brains. The precise specificity of the antibodies was determined mainly by enzyme-immunostaining on thin layer plates. MAbs M6703 and M6704 bound to C-series polysialogangliosides including GT3, GT2, GT1c, GQ1c, and GP1c isolated from cod fish brains, but never to A-series, B-series, or X-series gangliosides. On the other hand, MAb M7103 antibody has a rather narrow specificity, reacting with GT1c, GQ1c, and GP1c, but not with ganglioside GT3. This indicates that the epitopes defined by these two MAbs are different from each other. MAbs M6703 and M6704 recognize a trisialosyl residue, NeuAca 2-8NeuAcα2-8NeuAcα2-3, while M7103 requires both a trisialosyl residue and the gan-gliotetraosy backbone structure for binding. As compared to similar MAbs which have been reported in the literature. M6703 and M6704 are unique in that they react equally with all of the C-series gangliosides and belong to the IgG3 subclass. Using these two MAbs, the developmental changes of C-series gangliosides in chicken optic lobes during enceph-alogenesis have been demonstrated quantitatively. GT1c, GQ1c, and GP1c reached the highest level during the embryonic days 12-14, and GT3 was highly enriched at the 10th day and then gradually decreased. Very small amounts of GT3, GT1c, and GQ1c were still found in adult chick brains. These findings suggest that unusual C-series gangliosides on neural
cell surface membranes may be involved in the process of encephalogenesis.抄録全体を表示PDF形式でダウンロード (2710K) -
Naoyuki Murazumi, Kei-ichi Kumita, Yoshio Araki, Eiji Ito1988 年 104 巻 6 号 p. 980-984
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーAn enzyme which catalyzes the conversion of GlcNAc-PP-undecaprenol into ManNAc(β1→4)G1cNAc-PP-undecaprenol, a key lipid intermediate in the de novo synthesis of various teichoic acids, was partially purified from the 20, 000×g supernatant fraction of Bacillus subtilis AHU 1035 cell homogenate. By means of ammonium sulfate precipitation, gel chromatography, and ion-exchange chromatography, the enzyme was purified about 70-fold, giving a preparation virtually free from substances obstructive to measurement of the N-acetylmannosaminyltransferase reaction. The enzyme was shown to be specific to UDP-ManNAc. The Km value for UDP-ManNAc was 4.4μM, and the optimum pH was 7.3. The enzyme required 10 mM MgCl2, 0.3M KCl, 25% glycerol, and 0.1% Nonidet P-40 to function at full activity.抄録全体を表示PDF形式でダウンロード (598K) -
Kei-ichi Kumita, Naoyuki Murazumi, Yoshio Araki, Eiji Ito1988 年 104 巻 6 号 p. 985-988
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe glucosyltransferase which catalyzes the conversion of G1cNAc-PP-undecaprenol into Glc(β1→4)GlcNAc-PP-undecaprenol in the presence of UDP-glucose was solubilized from Bacillus coagulans AHU 1366 membranes by treatment with 0.1% Triton X-100 and partially purified by means of column chromatography on Sephacryl S-300 and DEAE-Sephacel. The final preparation was virtually free from other enzymes involved in the de novo synthesis of teichoic acid. The enzyme had a pH optimum of 6.6-8.0 and a Km value for UDP-glucose of 21 μM. The enzyme required 40 mM MgCl2, 0.6M KCl, and 0.1% Nonidet P-40 for full activity.抄録全体を表示PDF形式でダウンロード (409K) -
Sadayuki Matsuda1988 年 104 巻 6 号 p. 989-990
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーCa2+-binding of S-100 protein was studied using a Ca2+ electrode at pH 6.80. In the presence of 0.1 M KC1 and 10 mM MgCl2 (ionic strength 0.13), Ca2+-binding to S-100 protein occurred in three steps with positive cooperativity. The numbers of bound Ca2+ ions in the three steps were 2, 2, and 4. The Ca2+-binding constants were 6.9×103M-1, 2.9×103M-1, and 3.7×102M-1, respectively. The Ca2+-binding constants of the first and second steps obtained in the presence of 33.3 mM MgCl2 or 0.1 M KCl (ionic strength 0.10) were 1.4 times larger than those described above. This suggests that Mg2+ does not inhibit Ca2+-binding of S-100 protein. The increase of KC1 concentration from 0.1 to 0.2 M caused a decrease of the Ca2+-binding constants to ca. 50%.抄録全体を表示PDF形式でダウンロード (193K) -
Hiroshi Hirai, Do DE Lee, Shunji Natori, Kazuhisa Sekimizu1988 年 104 巻 6 号 p. 991-994
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe uridylation of U6 RNA in a nuclear extract of Ehrlich ascites tumor cells was examined. This reaction required ATP or GTP, although these nucleotides were not incorporated into U6 RNA itself. ATP and GTP could be replaced by their nonhydrolyzable analogues ATP γS and GTP γS. Therefore, hydrolysis of ATP or GTP is not necessary for the uridylation of U6 RNA, indicating that these nucleotides are effectors of this reaction. By chromatographies of a nuclear extract of Ehrlich ascites tumor cells on phosphocellulose and DEAE-cellulose, U6 RNA could be separated from an enzyme adding a uridine residue (s) to this RNA.抄録全体を表示PDF形式でダウンロード (1672K) -
Kazuhiro Kohama, Masatake Oosawa, Toshihide Ito, Koscak Maruyama1988 年 104 巻 6 号 p. 995-998
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーActin-modulating activity was analysed with the 16, 131-dalton calcium-binding light chain (CaLc, Kobayashi et al. (1988) J. Biol. Chem. 263, 305-313) of Physarum myosin, which is under an inhibitory Ca-control (Kohama and Kendrick-Jones (1986) J. Biochem. 99, 1433-1446). When skeletal muscle actin was polymerized in the presence of CaLc and Ca2+, increases in both viscosity and birefringence were reduced under high shear conditions. However, CaLc did not inhibit actin polymerization under no or low shearing forces, which was demonstrated by a variety of methods including fluorescence intensity measurements using pyrenyl actin. We propose that actin polymerized in the presence of CaLc and Ca2+ is easily fragmented under high shearing forces to produce the changes in viscosity and birefringence.抄録全体を表示PDF形式でダウンロード (1982K) -
Katsumi Matsuura, Michiko Hori, Toshio Satoh1988 年 104 巻 6 号 p. 1016-1020
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーWhen cells of the denitrifying phototrophic bacterium Rhodobacter sphaeroides forma sp. denitrificans were grown anaerobically under illumination in the presence of nitrate, the content of photosynthetic reaction centers per cellular protein was less than that in cells grown photosynthetically without nitrate under the same light intensity. The contents of cytochromes c1 and c2, which work in both photosynthetic and denitrifying electron transport systems, were almost constant, being independent of the presence of nitrate during growth. Consequently, the ratio of cytochromes c1 and c2 to the reaction center was more than three in the photo-denitrifying cells, whereas it was close to one in the photosynthetic cells under light-limiting conditions. In spite of the excess of cytochromes c1+c2, over the reaction center in the photo-denitrifying cells, all cytochromes c1+ c2, were oxidized by illumination within hundreds of milliseconds in the presence of antimycin. When glycerol was added to increase the viscosity in the periplasm, biphasic oxidation of cytochromes c1+c2 was apparent in the photo-denitifying cells with repetitive flashes. The fast phase oxidation, which took place instantaneously (<1 ms) after the first and second flashes, showed a similar pattern to the oxidation in the light-limiting photosynthetic cells. The rate of the slow phase oxidation was sensitive to viscosity and was thought toreflect a diffusion-controlled second-order reaction between cytochrome c2 and the reaction center. The biphasic oxidation of cytochromes c1+ c2suggests that these cytochromes exist in the photo-denitrifying cells as two different pools in relation to the reaction center.抄録全体を表示PDF形式でダウンロード (546K) -
Ayae Honda, Kenji Uéda, Kyosuke Nagata, Akira Ishihama1988 年 104 巻 6 号 p. 1021-1026
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーRibonucleoprotein (RNP) cores of influenza virus A/PR/8/34 were dissociated into RNA
polymerase (PB1-PB2-PA complex)-associated genome RNA and nuclear protein (NP) fractions by CsC1 centrifugation. The RNA polymerase-RNA complexes were capable of catalyzing the endonucleolytic cleavage of capped RNA, the initiation of primer-dependent RNA synthesis, and the synthesis of small-sized RNA, but were unable to synthesize template-sized RNA. By adding the NP protein to the RNA polymerase-RNA complexes, RNP (RNA polymerase-RNA-NP) complexes were reconstituted; they synthesized template-sized transcripts as did native RNP cores. These observations are consistent with the model where viral RNA polymerase is composed of the three P proteins while NP is essential for the elongation of RNA chains. RNP was completely dissociated into RNA-free proteins (PB1, PB2, PA, and NP) and a protein-free genome RNA fraction by centrifugation in cesium trifluoroacetate (CsTFA) and glycerol. By mixing the protein and RNA fractions, primer-dependent RNA-synthesizing activity was regained. These complexes, however, produced only small-sized RNA, presumably due to incorrect assembly of NP on viral RNA.抄録全体を表示PDF形式でダウンロード (4450K) -
Toshinobu Takashima, Sueo Matsumura, Toshitsugu Kariya, Toshiaki Sunag ...1988 年 104 巻 6 号 p. 1027-1035
発行日: 1988年
公開日: 2008/11/18
ジャーナル フリーThe physical properties of human platelet myosin in crude extracts were studied by means of Sepharose 4B gel filtration and sucrose density gradient centrifugation in the presence or absence of Mg-ATP. Platelet myosin extracted with a buffer containing 0-0.15 M KCl gave a Stokes radius of about 12.0-12.5 nm irrespective of the presence or absence of Mg-ATP. The sedimentation coefficients obtained in the presence of Mg-ATP were about 10-11 and 8.5S at 0.05-0.10 and 0.15 M KCl, respectively, whereas the values obtained in the absence of Mg-ATP were about 16, 9-12, and 8.5S at 0.05, 0.10, and 0.15 M KCl, respectively. The apparent molecular weight in the presence of Mg-ATP, therefore, was about 500, 000 and 420, 000 at 0.05-0.10 and 0.15 M KCl, respectively, while the molecular weight in the absence of Mg-ATP was about 790, 000, 460, 000-620, 000, and 440, 000 at 0.05, 0.10, and 0.15 M KCl, respectively. The purified monomeric platelet myosin that had been solubilized with Mg-ATP at 0.10 M KCl had a Stokes radius of about 12.5 nm, a sedimentation coefficient of about 9S, and an apparent molecular weight of 460, 000. On the other hand, while crude platelet myosin extracted at 0.6 M KCl with Mg-ATP gave a Stokes radius of about 20 nm, a sedimentation coefficient of about of 6S, and an apparent molecular weight of about 490, 000, each of these physical parameters obtained in the absence of Mg-ATP was much larger than that obtained in the presence of Mg-ATP because the myosin was associated with F-actin. In contrast, the Stokes radius, sedimentation coefficient, and molecular weight of purified monomeric platelet myosin at 0.6 M KCl were about 18.5 nm, 6S, and 460, 000, respectively, irrespective of the presence or absence of Mg-ATP. These results indicate that platelet myosin extracted at physiological ionic strength is mostly a partially folded monomeric molecule, that it dimerizes on decrease of ionic strength in the absence of Mg-ATP, and that it takes on an extended conformation on increase of ionic strength, and then associates with actin in the absence of Mg-ATP.抄録全体を表示PDF形式でダウンロード (4514K)
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