巻号一覧
76 巻, 5 号
選択された号の論文の28件中1～28を表示しています
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Toshio SHIBAOKA, Kiyoshi ISHIKURA, Takashi INATANI, Hiroyuki FUKUBE, K ...1974 年 76 巻 5 号 p. 909-914
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリー1. Inhibition by eleven substrate analogues of the hydrolytic reaction of phenyl α-maltoside into phenol and maltose catalyzed by saccharifying α-amylase [EC 3. 2. 1. 1] from B. subtilis*4 (1) was studied at 25°C and at pH 5.4.
2. Types of inhibition and inhibitor constants were determined at a fixed concentration of each analogue by varying the substrate concentration. The analogues showed competitive inhibition, except for β-maltose and eq-maltose (an equilibrium mixture of α- and β-anomers of maltose), which showed noncompetitive inhibition and mixed-type inhibition, respectively. Analysis of the results revealed that α-maltose is a competitive inhibitor.
3. Using eq-D-glucose, methyl α-D-glucoside, and β-maltose as inhibitors, the relationship between the concentration of inhibitor (i) and the reciprocal initial velocity (1/v) was investigated. The plot of 1/v versus i for each analogue was linear and in good agreement with the theoretical line expected from the type of inhibition and inhibitor constant Ki of each analogue as above determined.
4. The results are compared with those obtained for glucoamylase*5 [EC 3. 2. 1. 3] from Rh. delemar and Taka-amylase A*6 [EC 3. 2. 1. 1] reported previously.抄録全体を表示PDF形式でダウンロード (425K) -
Yukio KAWAMURA, Teruyoshi MATOBA, Tadao HATA, Etsushiro DOI1974 年 76 巻 5 号 p. 915-924
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーCathepsin A of large molecular size (cathepsin A, L) has been purified about 1, 000-fold from pig kidney.
1. The enzyme appeared homogeneous on ultracentrifugation and isoelectric focusing. The molecular weight (approximately 500, 000-600, 000) and isoelectric point (pI=5.8) were estimated.
2. The enzyme was stable at pH 5 to 6 in the presence of sucrose and KCl, and was optimally active at pH 5.2 to 5.7 for peptidase activity and at pH 8 for esterase activity.
3. The enzyme catalyzed the hydrolysis of all carbobenzoxy (Z)- and benzoyl (Bz)-dipeptides examined, which included Z-Phe-Ala, Z-Phe-Pro, and Bz-Gly-Arg. The rate of hydrolysis of Z-Phe-Ala, the best substrate, was 20 times higher than that for Z-Glu-Tyr. The carboxypeptidase nature of the enzyme was shown by its action on an oligopeptide.
4. The enzyme not only had peptidase activity but also esterase activity. In addition, amidase activity of the enzyme was confirmed by the hydrolysis of benzoyl-L-arginineamide (BAA), which is a typical substrate of cathepsin B. DFP and iodoacetamide completely inhibited these three activities.抄録全体を表示PDF形式でダウンロード (1633K) -
I. Purification and Complete Digestion with Pancreatic Ribonuclease A and Ribonuclease T1Kazuya NISHIKAWA, Shosuke TAKEMURA1974 年 76 巻 5 号 p. 925-934
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーA large amount of Torulopsis utilis 5S RNA was highly purified by successive chromatography on columns of DEAE-Sephadex A-50 and Sephadex G-100. The purified 5S RNA was completely digested with pancreatic ribonuclease A [EC 3. 1. 4. 22] and ribonuclease T1 [EC 3. 1. 4. 8], and the digestion products were separated and sequenced by column chromatographic procedures. The results of analyses of the two digests were in good agreement, and indicated that this RNA is composed of 121 nucleotide residues and contains no modified nucleotide as the other 5S RNA's so far sequenced do not. This RNA differs in several nucleotides from Saccharomyces carlsbergensis 5S RNA. The complete sequence of this RNA has been established after partial digestion with ribonucleases A, T1, and U2 as described in the subsequent paper.抄録全体を表示PDF形式でダウンロード (704K) -
II. Partial Digestion with Ribonucleases and Derivation of the Complete SequenceKazuya NISHIKAWA, Shosuke TAKEMURA1974 年 76 巻 5 号 p. 935-947
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーSeveral large oligonucleotide fragments were obtained by partial digestion of Torulopsis utilis 5S RNA with ribonucleases A [EC 3. 1. 4. 22], T1 [EC 3 .1. 4. 8], and U2. From the results of sequence analysis of these fragments and those described in the preceding paper, the complete nucleotide sequence of T. utilis 5S RNA was determined as follows: (p)pG-G-U-U-G-C-G-G-C-C-A-U-A-U-C-U-A-G-C-A-G-A-A-A-G-C-A-C-C-G-U-U-C-U-C-C-G-U-C-C-G-A-U-C-A-A-C-U-G-U-A-G-U-U-A-A-G-C-U-G-C-U-A-A-G-A-G-C-C-U-G-A-U-C-G-A-G-U-A-G-U-G-U-A-G-U-G-G-G-U-G-A-C-C-A-U-A-C-G-C-G-A-A-A-C-U-C-A-G-G-U-G-C-U-G-C-A-A-U-C-Uoh. A possible model for the secondary structure of this RNA is proposed and discussed in relation to the biological function of 5S RNA in ribosomes.抄録全体を表示PDF形式でダウンロード (802K) -
Formation of an EF-2•Ribosome•GDP ComplexHideharu TAIRA, Shin-ichiro EJIRI, Kensuke SHIMURA1974 年 76 巻 5 号 p. 949-957
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリー1. Silk gland EF-2 was found to be bound to ribosomes only in the presence of guanosine nucleotides, such as GTP, GDP or GMPPCP.
2. Incubation of EF-2, ribosomes, and [3H]GTP resulted in the formation of a highmolecular-weight [3H]GTP complex, which was retained on nitrocellulose filters and could be isolated by gel filtration. Most of the guanosine nucleotide present in this complex was recovered in the form of GDP.
3. The formation of the EF-2•ribosome•GDP complex was investigated. The reaction was very rapid and was completed within 5 sec at 0°. [3H]GDP could substitute for [3H]GTP in the formation of this complex. The amount of the EF-2•ribosome•GDP complex formed was stoichiometrically the same as that of the GTP hydrolysis concomitant with complex formation.
4. In the case of the Escherichia coli system, the complex formation was stimulated 2-fold by the addition of fusidic acid (1mM), while in the case of the silk gland system, such stimulation of complex formation was not observed.
5. The [3H]GDP bound to the complex was exchangeable with unlabelled GTP or GDP at 37°, but not at 0°. Fusidic acid inhibited this exchange reaction.
These results suggested that the hydrolysis of GTP by EF-2 and ribosomes proceeded through the intermediate formation of an EF-2•ribosome•GDP complex.抄録全体を表示PDF形式でダウンロード (714K) -
Activation and Properties of the EnzymeMichihiro KASAHARA, Yasuhiro ANRAKU1974 年 76 巻 5 号 p. 959-966
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe activation and properties of succinate dehydrogenase [EC 1. 3. 99. 1] of the membrane vesicles of Escherichia coli were studied. Most of the enzyme activity was found to be latent in the membrane vesicles and was activated by various treatments of the membranes, such as preincubation with succinate, addition of Triton X-100, or freeze-thawing.
Enzyme activation was achieved most effectively by preincubation of the membrane vesicles with succinate. Potassium cyanide enhanced the rate of activation by succinate.
The activation achieved by treating the membranes with Triton X-100 or freezethawing them was instantaneous. Magnesium ions inhibited the activation of enzyme.
The properties of succinate dehydrogenase of the membrane vesicles, including its Km values for succinate and phenazine methosulfate, and its pH optimum, are described.抄録全体を表示PDF形式でダウンロード (1336K) -
Mechanism of Selective Inhibition of the Systems by Zinc IonsMichihiro KASAHARA, Yasuhiro ANRAKU1974 年 76 巻 5 号 p. 967-976
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe mechanism of the selective inhibitions of succinate- and NADH oxidase activities of Escherichia coli membrane vesicles by zinc ions were studied.
Zinc ions strongly inhibited the succinate oxidase activity, but this inhibition was prevented by the presence of β-mercaptoethanol. p-Chloromercuribenzoate and N-ethylmaleimide also inhibited the activity. The succinate oxidase activity was slightly inhibited by photooxidation of the membrane vesicles with rose bengal. However, this was prevented by the presence of dithiothreitol.
The succinate dehydrogenase [EC 1. 3. 99. 1] activity of the membrane vesicles was found to be inhibited by zinc ions, even under anaerobic assay conditions. It was therefore concluded that zinc ions selectively inhibit the succinate oxidase system by blocking an active -SH residue(s), and that the site of the inhibition is located on succinate dehydrogenase. The mechanism of the inhibition is discussed briefly.
The NADH oxidase activity of the membrane vesicles was strongly inhibited by zinc ions and by photooxidation with rose bengal. The inhibition by zinc ions was not prevented by β-mercaptoethanol and N-ethylmaleimide was not inhibitory. The extent of inactivation of the oxidase activity by photooxidation depended on the pH and was not prevented by the presence of dithiothreitol. These, and other findings suggest that zinc ions inhibit the NADH oxidase activity by attacking a histidine residue(s) in the system, and that the site of the inhibition is before cytochrome b1 in the respiratory chain.
Other properties of the succinate-, NADH-, and D-(-)-lactate oxidase activities of the membrane vesicles, including their Km values for substrates and pH optima are reported.抄録全体を表示PDF形式でダウンロード (767K) -
XI. Mechanism of Energy Coupling Reaction for the Concentrative Uptake of Proline by Escherichia coli Membrane VesiclesMichihiro KASAHARA, Yasuhiro ANRAKU1974 年 76 巻 5 号 p. 977-983
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe membrane vesicles prepared from Escherichia coli W3092 could take up proline against a concentration gradient in the presence of succinate or D-(-)-lactate as energy source. The transport carrier of the membrane vesicles remained active and was found to be specific for proline.
Zinc ions strongly inhibited the uptake reaction initiated by succinate, the ID50 value being 15μM. The inhibition by zinc ions was non-competitive.
The K+-loaded membrane vesicles also took up praline against a concentration gradient when valinomycin was added to the reaction system. The valinomycininduced uptake of proline was not inhibited by zinc ions. Mercury ions inhibited strongly both succinate-driven and valinomycin-induced uptakes of proline by the membrane vesicles.
Evidence strongly suggests that energy coupled with the concentrative uptake of proline by the membrane vesicles is a membrane potential and that zinc ions inhibit the generation of a membrane potential by blocking oxidation of succinate.抄録全体を表示PDF形式でダウンロード (507K) -
VII. Interaction with Carboxylic AcidKenzaburo YOSHIDA, Takao NAKAMURA1974 年 76 巻 5 号 p. 985-990
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーCarboxylic acid inhibits the luminescent reaction of bacterial luciferase by competition with aldehyde. The inhibition was reversible during a single turnover of the enzyme. An unstable enzyme-FMN intermediate was rapidly formed on reaction of the luciferase-FMNH2 complex with O2 in the presence of excess carboxylic acid, and the fluorescence spectrum of this intermediate coincided with that of free FMN. The solvent effect on the fluorescence emission spectrum of FMN was examined in comparison with the luminescence spectrum of the luciferase reaction.抄録全体を表示PDF形式でダウンロード (1395K) -
Issei MABUCHI, Takashi SHIMIZU1974 年 76 巻 5 号 p. 991-999
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーAxonemes of Tetrahymena cilia were extracted with 1mM Tris-0.1mM EDTA (pH 8.2). From the extract, two forms of dynein [ciliary ATPase, EC 3. 6. 1. 3], namely 30 and 14S dyneins, were fractionated via sucrose density gradient centrifugation and analyzed by means of sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis.
The main polypeptide of 30S dynein fraction, which accounted for more than 70% of the total density of the stained gel, had a chain weight of 560, 000 daltons (polypeptide A). On the other hand, the main polypeptide of 14S dynein fraction, which accounted for more than 30% of the total density, had a chain weight of 520, 000 daltons (polypeptide B). These polypeptides were considered to be subunits of each dynein. Differences in the polypeptide chains of the two dyneins were confirmed by co-electrophoresis experiments. Analyses of the axonemes, outer fiber fraction and Tris-EDTA extract of the axonemes revealed that about 80% of polypeptide A plus B in the axonemes was extracted with Tris-EDTA.
Experiments on fresh and aged cilia showed that polypeptide B was not a degradation product of polypeptide A.抄録全体を表示PDF形式でダウンロード (3391K) -
Takashi SHIMIZU, Ichiro KIMURA1974 年 76 巻 5 号 p. 1001-1008
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe effects of N-ethylmaleimide (NEM) on ciliary ATPase (dyneins) [EC 3. 6. 1. 3] of Tetrahymena pyriformis were investigated. Like muscle myosin ATPase, 30S dynein ATPase was activated biphasically by NEM, while 14S dynein ATPase was simply inhibited. The maximal activation of 30S dynein ATPase was obtained by preincubation with NEM at a concentration of 50μM (0.23μmole NEM/mg protein) and the magnitude of activation was 2.5- to 3-fold.
The changes in the characteristics of 30S dynein ATPase caused by modification were studied in comparison with those of myosin ATPase. It was confirmed that 30S dynein ATPase was a myosin-like enzyme, though a few differences were found.
From recombination tests of modified 30S dynein with outer fibers, it was shown that at least three types of -SH groups are present in 30S dynein molecules; -SH groups responsible for recombination with outer fibers, for enhancement of the enzyme activity by their blockage, and for catalytic activity.抄録全体を表示PDF形式でダウンロード (608K) -
Hiroshi TANAKA, Kazuo IZAKI, Hajime TAKAHASHI1974 年 76 巻 5 号 p. 1009-1019
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe effects of two basic triphenylmethane dyes, crystal violet and ethyl violet, on the activity of a crude preparation of chloramphenicol acetyltransferase [EC 2. 3. 1. 28], obtained from R-factor-resistant Escherichia coli, were studied. Both compounds were shown to be strong inhibitors of this enzyme. Kinetic analyses of the molecular orders of participation of the substrates, chloramphenicol and acetyl-CoA, in the monoacetylation reaction, and of the inhibition by the two basic triphenylmethane dyes were carried out using a Hill-type equation. Inhibition of this enzyme by the dyes was found to be competitive for chloramphenicol and non-competitive for acetyl-CoA on the basis of Lineweaver-Burk plots. The relative affinities of chloramphenicol acetyltransferase for substrates and dyes were expressed by calculating dissociation constants for chloramphenicol and acetyl-CoA and inhibition constants for the dyes. The differences in Gibbs' free energy were evaluated from these constants. From these experiments, the synergistic action of chloramphenicol and the dyes on the growth of the resistant strain of E. coli seemed to be due to inhibition of chloramphenicol acetyltransferase by the dye.抄録全体を表示PDF形式でダウンロード (1421K) -
Taiji KATO, Makoto SASAKI1974 年 76 巻 5 号 p. 1021-1030
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe localization of the common antigenic determinant among four kinds of thiol proteases, papain [EC 3. 4. 22. 2], ficin [EC 3. 4. 22. 3], stem bromelain [EC 3. 4. 22. 4], and fruit bromelain [EC 3. 4. 22. 5] was investigated by estimating the immunological cross-reaction rate and the inhibition capacity of cross-reacting and noncross-reacting antibody species separable by means of enzyme immunoadsorbent. The existence of the common antigenic determinant was demonstrated by isolating a particular antibody population which could combine with all four enzyme immunoadsorbents. However the distribution of common regions between each pair of proteases was not identical. The anti-stem bromelain antibody cross-reacting with fruit bremelain was found to inhibit efficiently the catalytic activities of not only stem and fruit bromelains but also papain and ficin using benzoyl-L-arginine ethyl ester as a substrate. A comparison of the inhibition capacity between antibody species common to two enzymes and that common to three enzymes demonstrated that antibody common to the larger number of enzymes inhibited the catalytic activities of all four kinds of enzymes more markedly. It was concluded from these results that immunological cross-reaction made it possible to detect the conformational homology among four kinds of ontogenetically and phylogenetically differentiated thiol proteases, and that this homology did involve the active site and its proximate regions, suggesting that such regions related to the enzyme function have been best conserved in the long evolutionary process of this enzyme group, maintaining their similar proteolytic functions.抄録全体を表示PDF形式でダウンロード (803K) -
Isolation and Characterization of the Fragments Released from the Prothrombin by Activated Factor XTakashi MORITA, Hina NISHIBE, Sadaaki IWANAGA, Tomoji SUZUKI1974 年 76 巻 5 号 p. 1031-1048
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーProthrombin gave two fragments of 28, 000 and 57, 000 daltons on treatment with a relatively small amount of Factor Xa [EC 3. 4. 21. 6]. The fragment of 28, 000 daltons, which included the N-terminal portion of the parent molecule, consisted of a total of 121 amino acid residues and contained 18.5% carbohydrate. The sequence of the first 6 residues of its N-terminal, Ala-Asn-Lys-Gly-Phe-Leu-, was identical with that of the zymogen. The fragment of 57, 000 daltons had the N-terminal sequence Ser-Gly-Gly-, and C-terminal serine, and it consisted of a total of 437 amino acid residues and 6.6% carbohydrate. On activation, it developed thrombin [EC 3. 4. 21. 5] activity.
When prothrombin was incubated with a larger amount of Factor Xa, four fragments of 57, 000, 39, 000, 28, 000, and 14, 000 daltons were liberated. The fragment of 39, 000 daltons, which was derived from the fragment of 57, 000 daltons, was separated into two protein entities. One of these was α-thrombin and the other was a single polypeptide with N-terminal threonine. The amino acid composition and N-terminal residue of the single polypeptide were the same as those of α-thrombin. α-Thrombin seemed to be derived directly from the single polypeptide of 39, 000 daltons by cleavage of a peptide bond located on a peptide chain bridged by a disulfide linkage. The fragment of 14, 000 daltons consisted of a total of 104 amino acid residues and its N-terminal sequence, Ser-Gly-Gly, was identical with that of the fragment of 57, 000 daltons. The fragment of 14, 000 daltons was derived from the N-terminal portion of the fragment of 57, 000 daltons, and its formation was accompanied by the disappearance of the latter.
From these results, it seemed likely that activation of prothrombin was associated with three peptide-bond cleavages, yielding fragments of 28, 000 and 14, 000 daltons, and α-thrombin.抄録全体を表示PDF形式でダウンロード (4296K) -
I. Monovalent and Divalent Ion-dependent Conformation of the Active Site of Myosin A ATPaseTatsuhisa YAMASHITA, Toshiko HASUMI MIMURA1974 年 76 巻 5 号 p. 1049-1059
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe tryptic inactivation of EDTA-ATPase activity of myosin A was studied in 0.5M monovalent ion media at pH 7.6 and 20°.
1) Trypsin activity itself was affected by monovalent ions in the absence of divalent ions, but not by nucleotide regardless of the presence of monovalent and divalent ions.
2) Only in the absence of divalent ions were remarkable differences in the digestibility pattern observed between K+ and Na+ ions; in the K+ medium the inactivation rate was hardly promoted by ITP but was slightly increased by ATP and ADP. In the Na+ medium, on the other hand, these nucleotides, including ITP, markedly increased the rate of inactivation. Pyrophosphate showed almost the same potent effect as ATP in both media. In the presence of divalent ions, however, nucleotides strongly accelerated the inactivation of ATPase activity and no differences between K+ and Na+ were observed in the digestibility pattern. The mode of inactivation in the absence of divalent cations was first order, while the semilogarithmic plot of the inactivation rate in the presence of Mg2+ was biphasic in the presence of ATP.
3) A plot of the degree of tryptic inactivation of ATPase [EC 3. 6. 1. 3] activity in the presence of ATP and ITP against the crystal ionic radius of monovalent ions from 0.6 (Li+) to 1.7 Å (Cs+) was bell-shaped, with a minimum in K+ medium (1.33 Å). The accelerating effect of ITP was not observed in K+ and NH4+ media, where ATP was still effective.
4) The actions of K+ and Na+ on the tryptic digestibility were independent of each other but were competitive on the catalytic activity.
5) When a specific sulfhydryl group, SI, was blocked with N-ethylmaleimide, myosin became more susceptible to trypsin. The typical effect of nucleotides seen in intact myosin was hardly observed in K+ medium, though the nucleotides were still effective in Na+ medium.
From the experimental data obtained, the ion-dependent conformations of the active site of myosin ATPase were discussed.抄録全体を表示PDF形式でダウンロード (770K) -
Yasushi SAITO, Nobuo MATSUOKA, Hiromichi OKUDA, Setsuro FUJII1974 年 76 巻 5 号 p. 1061-1065
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーLipid micelles were prepared from isolated fat cells by disruption in a hypotonic medium. On addition of 10-6M adenosine 3', 5'-monophosphate (cyclic AMP) or dibutyryl cyclic AMP (DBcAMP) the protein kinase [EC 2. 7. 1. 37] activity but not the lipolysis of these lipid micelles increased greatly. On the other hand, the addition of other lipolytic agents, such as theophylline or adrenaline, or of phospholipase C [EC 3. 1. 4. 3] and CaCl2, increased lipolysis but not protein kinase activity. These results suggest that activation of protein kinase did not necessarily occur on stimulation of lipolysis. Incubation of these lipid micelles with adrenaline resulted in marked lipolysis but no increase in protein kinase activity. These results suggest that the lipolytic action of adrenaline in these lipid micelles was not due to increased lipase [EC 3. 1. 1. 3] activity, as reported by Huttunen and Steinberg (1). The extent of activation of hormone-sensitive lipase by cyclic AMP using the system of Huttunen and Steinberg was very low compared with the extent of stimulation of lipolysis in the lipid micelles or fat cells. Furthermore, cyclic AMP was found to activate not only hormone-sensitive lipase but also lipoprotein lipase, steapsin and kidney and liver lipases.
The mode of activation of lipolysis is discussed on the basis of these results.抄録全体を表示PDF形式でダウンロード (346K) -
Hitoshi ARITA, Jun'ichi KAWANAMI1974 年 76 巻 5 号 p. 1067-1074
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーCeramide mono-, di-, and trihexoside, two globosides, and hematoside were isolated from metastatic rat mammary tumor (MRMT-1) by column chromatography on silicic acid and preparative thin-layer chromatography. Each glycolipid was analyzed for fatty acids, long chain bases, and sugars. A combination of periodate oxidation, specific enzymatic hydrolysis, permethylation, and gas chromatographic studies of the sugar moieties established the arrangement of sugars, their anomeric configurations, and positions of their anomeric linkages in the lipids. The main glycolipids were two globosides having structure identical with cytolipin R; N-acetylgalactosaminyl(β1→3) galactosyl (α1→3) galactosyl (β1→4) glucosyl-ceramide. The only structural differences were in their component fatty acid composition. The structure of ceramide trisaccharide was galactosyl (α1→3) galactosyl (β1→4) glucosyl-ceramide, which is assumed to be a possible precursor of cytolipin R. The hematoside from this tumor was N-acetylneuraminyl-lactosyl-ceramide.抄録全体を表示PDF形式でダウンロード (4698K) -
Akira HACHIMORI, Mieko ITOH, Tatsuya SAMEJIMA1974 年 76 巻 5 号 p. 1075-1081
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーGlutamine synthetase [EC 6. 3. 1. 2] from yeast (Saccharomyces cerevisiae) was purified to a homogeneous state both ultracentrifugally and electrophoretically. The enzyme has a molecular weight of 630, 000 and a sedimentation coefficient (S0.2%20, W) of 18.9S. The molecular weight of the subunit dissociated by 0.1% sodium dodecyl sulfate containing 1mM 2-mercaptoethanol is 61, 000, which suggests the presence of 10 subunits in the native molecule. The amino acid composition is similar to those of the enzymes from E. coli, B. subtilis, and B. stearothermophilus. The enzyme requires divalent cations such as Mg2+ and Mn2+ for activity. The enzyme can use D-glutamic acid as a substrate in place of L-glutamic acid. Glycine, alanine, tryptophan, histidine, AMP, and CTP all inhibit the enzyme activity to various extents.抄録全体を表示PDF形式でダウンロード (1333K) -
IV. Quantitative Estimation of the Rates of Synthesis of Pyocin R Subunit ProteinsTomoyuki SHINOMIYA1974 年 76 巻 5 号 p. 1083-1094
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーPyocin R, a bacteriocin produced by Pseudomonas aeruginosa strain P15, has a complex structure, resembling a bacteriophage tail, and is composed of more than 400 molecules with about 20 different types of subunits. The rates of synthesis of these subunits at a late stage of mitomycin C-induced production were measured. It was found that the subunit proteins were synthesized in proportion to their contents in mature pyocin particles.
The rates of integration of labelled proteins into pyocin particles were determined by pulse-chase experiments. Most subunits were integrated with apparent first-order kinetics with half-life times of 4 to 14min, and the integration of total structural proteins into pyocin particles had an average half-life of 8min. Two subunits, however, behaved differently, and showed lag times of about 6min before being detected in pyocin particles. The results are discussed in relation to the events occurring in the morphogenesis of pyocin R.
Revised data on the subunit composition of pyocin Rare presented and its characteristics discussed.抄録全体を表示PDF形式でダウンロード (937K) -
Meir PERL1974 年 76 巻 5 号 p. 1095-1101
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe carboxylation of phosphoenolpyruvate, catalyzed by a partially purified enzyme extracted from Euglena gracilis cells, is inhibited by intermediates of the tricarboxylic acid cycle and by 3-phosphoglycerate. The presence of two PEP-carboxylating protein fractions which could be separated by ion exchange chromatography was demonstrated. It was found that they differ in apparent Km, with respect to CO32- and PEP, and are differently affected by the tricarboxylic acid cycle intermediates and 3-PGA.
A comparison of the enzyme obtained from dark-grown cells and green (lightgrown) cells indicates that one fraction is present at a relatively higher activity in green cells (Fraction A) while the other is more active in dark-grown cells (Fraction B).抄録全体を表示PDF形式でダウンロード (400K) -
Shinichi SUGIMOTO, Isamu SHIIO1974 年 76 巻 5 号 p. 1103-1111
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe regulation and some other properties of prephenate dehydratase [prephenate hydro-lyase (decarboxylating), EC 4. 2. 1. 51] of Brevibacterium flavum were studied. Prephenate dehydratase was purified about 38-fold from crude extracts of a tyrosine auxotroph, BX-1. The optimum pH of the reaction was 6.5 in potassium phosphate buffer. The relationship between the enzyme concentration and activity was linear in the presence of tyrosine but not in its absence. Km for prephenate was 54μM. The enzyme was completely inhibited by phenylalanine or by tryptophan, while tyrosine not only reversed the inhibition competitively but also stimulated the enzyme activity about 10-fold. The concentration of tyrosine giving half-maximum activation was 1.6μM. Tyrosine affected both the Km value and the maximum reaction velocity. Similarly, phenylalanine and tryptophan were mixed-type inhibitors. The concentration of tryptophan giving 50% inhibition was 25μM, 10 times that of phenylalanine, 2.5μM. None of the tyrosine and phenylalanine analogues tested strongly activated the enzyme, but several analogues inhibited it, as did phenylalanine. The molecular weight which was estimated to be 2.2×105 by gel filtration experiments; this value was not affected by tyrosine or by phenylalanine. On the basis of these results, the regulatory mechanism of aromatic amino acid biosynthesis in B. flavum was discussed.抄録全体を表示PDF形式でダウンロード (706K) -
Kazuo TERAO, Kunio TSURUGI, Kikuo OGATA1974 年 76 巻 5 号 p. 1113-1122
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーStudies were made on whether ribosomal structural proteins were exchangeable with cell-sap proteins in vitro, by incubating unlabeled ribosomes with labeled cell sap and vice versa. The following results were obtained.
(1) When cell-sap proteins of rat liver labeled for 12 hr in vivo were incubated with liver ribosomes, some of the protein combined with the ribosomes even at 2° to 5°. However, almost all this bound radioactivity could be released by centrifugaof the ribosomes through medium of high KCl concentration followed by EDTA-treatment. EDTA-treatment of liver ribosomes labeled for 12 hr in vivo resulted in release of part of the radioactivity in the low-S region. Release of radioactivity by EDTA-treatment was negligible when labeled ribosomes were incubated with cell sap or in Medium A' at 2° and then purified by discontinuous sucrose gradient centrifugation.
(2) The amount of labeled cell-sap proteins bound to ribosomes was more on incubation at 30° than on incubation at 2° and some of this could not be released from the ribosomal subunits by EDTA-treatment. On the other hand, the specific radioactivity of labeled ribosomes preincubated either with cell sap or in Medium A' was only slightly lower after preincubation at 30° than after preincubation at 2°.
(3) Employing highly labeled cell sap and unlabeled ribosomes from regenerating rat liver, it was found that labeled cell-sap proteins bound to ribosomes at 37° could be distinguished from ribosomal structural proteins by polyacrylamide-gel electrophoresis, especially by two-dimensional electrophoresis.
These results indicate that ribosomal structural proteins are not exchangeable with cell-sap proteins on incubation in vitro, although cell-sap proteins bound to ribosomes include proteins functioning in peptide bond synthesis on liver ribosomes.抄録全体を表示PDF形式でダウンロード (1729K) -
II. Ketone Bodies Formation from α-Ketoisocaproate, the Keto-analogue of Leucine, by Rat Liver MitochondriaChiseko NODA, Akira ICHIHARA1974 年 76 巻 5 号 p. 1123-1130
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーα-Ketoisocaproate (KIC), the keto-analogue of leucine, was metabolized to ketone bodies by rat liver mitochondria in vitro on addition of ADP, Mg2+, and an oxidizable substrate, such as succinate or α-ketoglutarate. Formation of ketone bodies from KIC showed a biphasic increase with time, being slow in the first 20min and then rapid and linear with time. The disappearance of KIC was proportional to ketone bodies formation. No slow phase was seen using mitochondria that had been preincubated with the above energy generating system. The two phases were not affected by addition of CoA, NAD+, or carnitine, but increase of succinate concentration over 2.5mM prolonged the slow phase. The time course of ATP formation and succinate oxidation suggested that both decrease of oxidizable substrate and increase of ATP concentration may be necessary for the rapid phase. During oxidation of KIC, cytochrome b was reduced in the presence of ADP and oxidation of added succinate predominated over that of KIC. Addition of an ATP generating system (phosphoenolpyruvate, pyruvate kinase [EC 2. 7. 1.40], and ATP) with dinitrophenol partially abolished the slow phase. Addition of ATP alone did not enhance the oxidation.
From these results it is likely that KIC oxidation is controlled by the concentration of oxidizable substrates, which may monopolize the electron transport system in the first phase, but provide the necessary amount of ATP for the later phase.抄録全体を表示PDF形式でダウンロード (566K) -
Yumiko TOMITA, Tetsuro YOSHIMURA, Katsuyuki IMAI1974 年 76 巻 5 号 p. 1131-1138
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーThe effect of poly-L-lysine on α-ketoglutarate dehydrogenase (α-KGDH) was investigated further. Addition of poly-L-lysine to the enzyme produced an insoluble polypeptide-enzyme complex which dissolved on further addition of polypeptide to the enzyme (1). Supernatant and precipitate fractions of the solution containing the polypeptide-enzyme complex were obtained using a Millipore filter or by centrifugation and their enzyme activities were analyzed by sucrose density gradient centrifugation. Analysis of the supernatant fractions indicated that with a ratio (w/w) of polyL-lysine to α-KGDH of 5.0, lipoamide dehydrogenase [EC 1. 6. 4. 3] activity was found only in fractions corresponding to free lipoamide dehydrogenase. The peak of decarboxylase [EC 1. 2. 4. 2] activity appeared in a position close to that of free lipoamide dehydrogenase. The two enzyme activities were not observed in fractions of α-KGDH. However, analysis of precipitated material dissolved in 1M KCl showed that, with a lower ratio of poly-L-lysine to the enzyme, lipoamide dehydrogenase and decarboxylase activities were associated with α-KGDH. On increasing the ratio of poly-L-lysine to enzyme, the peaks of lipoamide dehydrogenase and decarboxylase sedimented more slowly. These results suggested that, on binding with excess polyL-lysine, lipoamide dehydrogenase and decarboxylase dissociated from the original enzyme and that the resolution was dependent on the ratio of poly-L-lysine to enzyme. α-KGDH activity was restored almost completely by the addition of poly-L-glutamate to the enzyme resolved with poly-L-lysine. On sucrose density gradient centrifugation the restored activity was detected in fractions corresponding to the original α-KGDH. The effect of poly-L-lysine on the enzyme is discussed on the basis of these results and those reported previously.抄録全体を表示PDF形式でダウンロード (601K) -
Kozo ISHIDATE, Michinao MIZUGAKI, Mitsuru UCHIYAMA1974 年 76 巻 5 号 p. 1139-1142
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーPDF形式でダウンロード (284K) -
Ken-ichi TSUTSUMI, Reiko MAJIMA, Kensuke SHIMURA1974 年 76 巻 5 号 p. 1143-1145
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーPresumed tRNA precursors having molecular sizes of more than 4S were isolated from a cytoplasmic fraction of the silk glands of Bombyx mori. These precursor molecules were demonstrated to be converted into 4 S RNA by a crude enzyme fraction prepared from an extract of silk gland ribosomes with 1.0M NH4Cl.抄録全体を表示PDF形式でダウンロード (197K) -
Kiyoshi FURUICHI, Mikiko KATO, Tohoru NAKAMURA, Jiro KOYAMA1974 年 76 巻 5 号 p. 1147-1149
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーIn general, immunization of guinea pigs with hapten-protein conjugates using the usual immunization techniques induces concomitant production of IgGI and IgG2 anti-hapten antibodies. However, when lipopolysaccharides (LPS) of Escherichia coli were used as a carrier of 2, 4-dinitrophenyl residues (DNP) and injected intraperitoneally with Freund's incomplete adjuvant (FIA), anti-DNP antibody production was enhanced markedly as compared with bovine serum albumin (BSA). Furthermore, the DNP-LPS was found to induce preferential production of IgG2 anti-DNP antibody not accompanied by IgG1 anti-DNP antibody.抄録全体を表示PDF形式でダウンロード (1040K) -
Koichiro TAKESHIGE, Shigeki MINAKAMI1974 年 76 巻 5 号 p. 1151-1153
発行日: 1974/11/25
公開日: 2008/11/18
ジャーナル フリーNADPH-dependent methanol oxidation was observed in a system consisting of catalase [EC 1. 11. 1. 6], NADPH-cytochrome c reductase [EC 1. 6. 2. 4], and a low molecular weight factor from trypsin digested hepatic microsomes. The factor inhibited NADPHdependent lipid peroxidation in microsomes but did not affect drug hydroxylation.抄録全体を表示PDF形式でダウンロード (199K)
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