巻号一覧
79 巻, 3 号
選択された号の論文の26件中1～26を表示しています
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Purification and CharacterizationTakashi KAGEYAMA, Kenji TAKAHASHI1976 年 79 巻 3 号 p. 455-468
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーFive pepsinogens were purified from gastric mucosa of Japanese monkey by DEAE- cellulose column chromatography and Sephadex G-100 gel filtration. Each was shown to be homogeneous by polyacrylamide disc gel electrophoresis. They were designated as pepsinogens I, II, III-1, III-2, and III-3, respectively, based on the elution profile on DEAE-cellulose chromatography. The molecular weights of pepsinogens I and II were 48, 000 and 43, 000, respectively, and those of the other three were 40, 000. Each pepsinogen was converted to pepsin [EC 3.4.23.1] by acidification, and some charac- teristics, e. g. the pH dependence of activity, sensitivity to various inhibitors, stability to alkali, and hydrolytic activity toward N-acetyl-L-phenylalanyl-3, 5-diiodo-L-tyrosine (APDT), were determined. The characteristics of pepsins I and II were the same, and those of pepsins III-1, IIII-2, and III-3 were similar. Pepsin III-3 showed high stability to alkali (pH 8.0), while the others were less stable. Each pepsin hydrolyzed APDT and was inhibited by acid protease-specific inhibitors, e. g. pepstain, diazoacetyl-DL-norleucine methyl ester (DAN), 1, 2-epoxy-3-(p-nitrophenoxy)propane (EPNP), and p-bromophenacyl bromide. The amino acid compositions of these pepsinogens and pepsins were analyzed. The compositions of pepsins I and II were the same, indicating that they are the same protein, and those of pepsins III-1, III-2, and III-3 resembled that of human pepsin. The diversity of pepsinogens and pepsins is discussed in comparison with pepsinogens and pepsins from other animals.抄録全体を表示PDF形式でダウンロード (1588K) -
II. Thermal Stability of the Thermophilic α-AmylaseAkio HASEGAWA, Kazutomo IMAHORI1976 年 79 巻 3 号 p. 469-477
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe effect of pH, metal ions, and denaturing reagents on the thermal stability of thermophilic a-amylase [EC 3.2.1.1] were examined. The enzyme was most stable at around pH 9.2, which is coincident with the isoelectric point of the enzyme. The stability of the enzyme was increased by the addition of calcium, strontium, and sodium ions. The addition of calcium ions markedly stabilized the enzyme. The protective effects of calcium and sodium ions were additive. At room temperature, no detectable destruction of the helical structure of the enzyme was observed after incubation for 1 hr in the presence of 1% sodium dodecylsulfate, 8M urea or 6M guanidine-HC1. The addition of 8M urea or 6M guanidine-HCI lowered the thermal denaturation temperature of the enzyme. The enzyme contained one atom of tightly bound intrinsic calcium per molecule which could not be removed by electrodialysis unless the enzyme was denatured. The rate constants of inactivation and denatura- tion reactions in the absence and presence of calcium ions were measured and thermo- dynamic parameters were determined. The presence of calcium ions caused a remarkable decrease in the activation entropy.抄録全体を表示PDF形式でダウンロード (592K) -
Yoshiki TAKESUE, Yoshimi NISHI1976 年 79 巻 3 号 p. 479-488
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe topographical relationship between sucrase [EC 3.2.1. 26] and leucine β-naphthyl-amidase (LNAase) on the microvilli membrane of rabbit small-intestinal mucosal cells was studied assuming that where enzymes with different antigenicities, A and B, are situated in close proximity on the surface of microvilli vesicles, the agglutination of vesicles by anti-A antibody is inhibited by the previous binding of monovalent fragments of anti-B antibody to enzyme B on the surface of vesicles. Like anti-sucrase antibody, anti-LNAase antibody quantitatively agglutinated microvilli vesicles. It inhibited the membrane-bound LNAase activity in the same manner as the deter-gent-solubilized activity. This inhibitory effect of anti-LNAase antibody was not interfered with by monovalent fragments of anti-sucrase antibody. However, the monovalent fragments inhibited vesicle agglutination by anti-LNAase antibody as well as by anti-sucrase antibody. These results indicate that LNAase is located on the outer surface of microvilli vesicles and suggest that LNAase and sucrase are situated in close proximity on the membrane surface of microvilli vesicles.抄録全体を表示PDF形式でダウンロード (780K) -
VIII. FMN-H2O2 Initiated Bioluminescence and the Thermodynamics of the Elementary Steps of the Luciferase ReactionTakahide WATANABE, Takao NAKAMURA1976 年 79 巻 3 号 p. 489-495
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーBacterial luciferase from Photobacterium phosohoreum was found to produce biolumi-nescence on reaction with FMN and H2O2 in the presence of aldehyde. This lumi-nescence is presumably produced by the same X1 intermediate as that found in FMNH2-O2 initiated luminescence. From the ratio of the light intensities of the FMN-H2O2 initiated and FMNH2-O2 initiated reactions, we calculated the association constant of the reaction, luciferase+FMN+H2O2_??_X1, and estimated its temper-ature dependence. From these results we calculated the thermodynamic parameters of the reaction, luciferase+FMNH2+O 2_??_X1. We found that the free energy level of X1 is only 3.2 kcal below that of free FMN and H2O2. We also estimated the thermodynamic parameters of other steps of the luminescent reaction. The values obtained showed that the formation of X1 from luciferase, FMNH2 and O2 involves a positive entropy change, but the intermediate is in a state stabilized against decomposition. Results also suggest a considerable degree of electronic rearrangement on formation of the excited-state molecule from the X1-aldehyde complex.抄録全体を表示PDF形式でダウンロード (478K) -
Tatsuo ERABI, Tomihiko HIGUTI, Kumiko SAKATA, Tomisaburo KAKUNO, Jinpe ...1976 年 79 巻 3 号 p. 497-503
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーPolarographic studies on oxidation-reduction components bound with chromatophores from Rhodospirillum rubrum were carried out at 24°
1. Using a carbon-paste electrode as the working electrode, polarographic waves characteristic of oxidation-reduction components were observed in the presence, but not in the absence of Triton X-100; these waves were therefore measured in the presence of the detergent.
2. At least two kinds of oxidation-reduction components were detectable, having different half-wave potentials (E1/2); at pH 7, one had an E1, 2 value of +275 mV (POC+275) and the other had a value of +60mV (POC+60).
3. POC+275 was reduced by succinate and by NADH. Both reductions were almost completely inhibited by antimycin A, which hardly affected the reductions of ubi- quinone-10 by succinate and by NADH. Most POC+275 molecules were not reduced by the substrates when quinones were extracted from the chromatophores, and the reductions were mostly restored when ubiquinone-10 was re-added. This indicates that POC+275 is functional between ubiquinone-10 and cytochrome c2 in the electron transport system.
4. POC+60 was reduced by succinate, but hardly at all by NADH. The reduction of POC+60 was not influenced either by the addition of antimycin A or by the extrac-tion of quinones. This suggests that POC+60 is functional in the process from suc-cinate dehydrogenase [EC 1.3.99.1] to ubiquinone-10 in the electron transport system.
5. Of the POC+275 reducible by dithionite, approximately 70% could be reduced in the absence of Triton X-100, provided that the potential of the working electrode immersed in chromatophore suspensions was set at potentials of 0mV or lower and抄録全体を表示PDF形式でダウンロード (574K) -
Jun-ichi KUMAGAI, Takahisa OHTA, Kazutomo IMAHORI1976 年 79 巻 3 号 p. 505-511
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe conformational changes of ribonucleic acid induced by heat treatment were studied by measurements of fluorescence polarization, circular dichroism, and ultraviolet absorption. The fluorescence polarization of proflavine covalently bound to the 3'-end of 16S ribosomal RNA of Escherichia coli and that of ethenoadenosine conjugated to the 5'-end of the RNA indicated that a conformational difference existed between heat-treated and untreated samples of the RNA in the regions near the 3'- and 5'- ends. Comparison of the fluorescence polarization data with other optical measure- ments indicated that the local conformation around the 3'- and 5'-ends of the RNA was converted to a more rigid and stable form by the heat treatment, while the gross conformation did not appear to change.抄録全体を表示PDF形式でダウンロード (538K) -
Masanobu JANADO, Kazuko SHIMADA, Toshiro NISHIDA1976 年 79 巻 3 号 p. 513-520
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe thermodynamic properties of the adsorption of sulfanilamide, phenol and n-butanol on Bio-Gel beads have been studied. Bio-Gel was chosen as the adsorbent as it possesses both hydrophobic and hydrophilic sites on its surface. Adsorption of the former two adsorbates was found to be exothermic, and the relevant thermodynamic parameters at 20° are in the ranges: ΔH°=-2.7 to -5.4 kcal/mole; ΔF°=-6.0 to -7.6 kcal/mole; ΔS°=+7.7 to +11.6 e. u. In the presence of urea, adsorption of sulfanilamide and phenol was partially disrupted. This, together with the large entropy gain of the process, indicates that both hydrogen bonding and hydrophobic bonding contribute cooperatively to the adsorption. On the contrary, adsorption of n-butanol, which was not susceptible to urea, was an endothermic process with the parameters, ΔH°=+5.8 kcal/mole, ΔF°=-1.8 kcal/mole, and ΔS°=+26.1 e.u. at 20°. These data conform to the thermodynamic properties of hydrophobic bond formation. Finally, possible implications of these data in the structural assembly of lipoprotein molecules are discussed.抄録全体を表示PDF形式でダウンロード (608K) -
Takashi OBINATA, Takayuki HASEGAWA, Tomoh MASAKI, Teru HAYASHI1976 年 79 巻 3 号 p. 521-531
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe subunit composition and immunological properties of two types of myosins, the 3 S and 6 S myosin components, from skeletal muscle of early chick embryos were studied by SDS-acrylamide gel electrophoresis and immunodiffusion techniques.
It was shown that the 6 S myosin in the early embryonic stage was composed of two heavy chains and three kinds of light chains, as is well-known in the complete myosin molecule, having the same molecular weights and the same antigenicities as corresponding subunits of the myosin from adult chicken skeletal muscle. The heavy chain of 6S myosin was also reactive with the antibody against the heavy chain of cardiac myosin. The embryonic 3 S myosin was shown to be composed of a heavy chain which was roughly the same in molecular weight but not the same in antigenicity as those of adult or embryonic 6 S myosin. No light chains were detected either electrophoretically or immunologically in the 3 S myosin component.抄録全体を表示PDF形式でダウンロード (7551K) -
Shigeru KUROOKA, Masahisa HASHIMOTO, Masatsugu TOMITA, Akio MAKI, Yosh ...1976 年 79 巻 3 号 p. 533-541
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーAbout 100 S-fatty acyl thiol compounds designed as substrates for pancreatic lipase [EC 3.1.1.3] were synthesized and tested for susceptibility to hydrolysis by hog pancreatic lipase and hog hepatic carboxylic esterase [EC 3.1.1.1] using 5, 5'-dithio- bis(2-nitrobenzoic acid) as a chromogenic reagent to determine the hydrolytic rates of their S-acyl bonds.
In general, the hydrolytic rates of S-acyl bonds by the lipase were fast with thioglycerol type thiol moieties, slow with dithioethyleneglycol type or monothiol type, and negligible with thiopolyol type. As for the acyl moieties, the hydrolysis of the S-acyl bonds was fast with C3-5 acyl groups, followed by C6-8 acyl groups, and the rate decreased as the acyl chain length deviated from these values or branched. On the other hand, the hydrolysis of S-acyl bonds by the esterase occurred with all types of S-acyl esters except for esters of long S-acyl chains.
Of all the compounds tested with the lipase, the rate of hydrolysis of S-acyl bond was maximum with 2, 3-dimercaptopropan-1-ol tributyroate [I], high with 3-mercaptopropane-1, 2-diol tributyroate [II], but negligible with the analogous com- pound, 1, 3-dimercaptopropan-2-ol tributyroate.
Compounds [I] and [II] may be practically useful as substrates for lipase assay in human serum samples pretreated with phenylmethylsulfonyl fluoride, a potent inhibitor against both serum arylesterase [EC 3.1.1.2] and hepatic esterase, which attack [I] and [II].抄録全体を表示PDF形式でダウンロード (643K) -
Fusae KANDA, Toshie KAMIKASHI, Sadahiko ISHIBASHI1976 年 79 巻 3 号 p. 543-548
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーA difference in the mode of inhibition of hexokinase [EC 2.7.1.1] isoenzymes by p-chloromercuribenzenesulfonate was confirmed with respect to glucose between two Type I isoenzyme preparations purified from the kidney and spleen of rat. Essentially the same difference was observed when galactose was used as the substrate in place of glucose, as the kidney Type I isoenzyme was inhibited in a competitive manner while the spleen counterpart was inhibited in a non-competitive manner by sulfhydryl inhibitor. Both the Type I isoenzymes, however, were competitively inhibited by other mercurial sulfhydryl inhibitors, methyl and butyl mercuric chlorides. On the other hand, the Type II hexokinase isoenzymes purified from the muscle, heart, and spleen were all inhibited competitively by p-chloromercuribenzenesulfonate with respect to glucose. The mechanism of competitive inhibition of the hexokinase isoenzymes by sulfhydryl inhibitors was discussed in view of the difference in the mode of action of the mercurials with different isoenzymes.抄録全体を表示PDF形式でダウンロード (472K) -
Daizo KOGA, Katsuya HAYASHI1976 年 79 巻 3 号 p. 549-558
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe activation process of pepsinogen was analyzed by a combination of computer simulation and experiment. In order to investigate in detail the behavior of the basic schemes proposed in the previous study, further computer simulations were conducted. Some experiments were performed based on the information obtained. The changes in the UV difference spectrum in the early stage was measured by the stopped-flow technique and the conversion of pepsinogen to pepsin [EC 3.4.23.1] was followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Furthermore, on the basis of the experimental results, the most reasonable scheme was selected and modified. As a result, a scheme for the activation process of pepsinogen was obtained (Scheme 8). On the basis of the above analyses, it was assumed that the first step and the third step are pH-dependent based on the change in the UV spectrum, that the second step is a nonlinear reaction containing a looped reaction with a dimeric intermediate (in this step, peptide fragments are released and pep- sinogen is converted to a pepsin-like molecule), and that the third step is an equilib- rium reaction involving proton binding.抄録全体を表示PDF形式でダウンロード (814K) -
III. Isolation of Five Polypeptide Inhibitors from the Venoms of Hemachatus hemachatus (Ringhal's Cobra) and Naja nivea (Cape Cobra) and the Complete Amino Acid Sequences of Two of ThemYasuji HOKAMA, Sadaaki IWANAGA, Tsuru TATSUKI, Tomoji SUZUKI1976 年 79 巻 3 号 p. 559-578
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーFive proteinase inhibitors which all inhibit the activity of bovine trypsin [EC 3.4.21.4] were isolated from African Elapid venoms of Hemachatus haemachatus (HHV, Ringhal's cobra) and Naja nivea (NNV, Cape cobra). All the inhibitors were essen-tially homogeneous by polyacrylamide gel electrophoresis in the presence or absence of sodium dodecylsulfate. Amino acid analysis and terminal analysis also supported their chemical homogeneities, except for one of the two inhibitors from Hemachatus haemachatus venom. The isolated inhibitors had a molecular weight of about 6, 500, consisting of 52 to 57 amino acid residues, and they were all devoid of tryptophan. However, their amino acid compositions differed from each other. One of the three inhibitors isolated from Naja nivea venom, designated NNV inhibitor la, was unique, in that 4 half-cystinyl residues per mole of the polypeptide were present, whereas all the others contained six residues.
Of the isolated proteinase inhibitors, the complete amino acid sequences of two major inhibitors were established by manual and automatic Edman degradations and standard enzymatic techniques. Each of the inhibitors, designated HHV inhibitor II and NNV inhibitor II, consisted of 57 amino acid with arginine and glycine at the NH2-and COOH-termini, respectively. Both contained six half-cystines in disulfide linkages, and their overall amino acid sequences were similar, showing 91% homology. The two inhibitors differed in sequence by only five amino acid replacements, Asp-3 to Arg; Tyr-17 to Arg; Leu-25 to Arg; Gln-32 to Glu; and Arg-52 to His, in the 57 residue peptide chain.
Comparing the amino acid sequences of these two cobra venom inhibitors with those of Russell's viper venom inhibitor II and bovine pancreatic trypsin inhibitor (BPTI), about 50% homology was found in their sequences. The 6 half-cystinyl residues of these inhibitors were in the same linear positions. Moreover, the regions which are structurally and functionally important in the well-known BPTI molecule were found with extremely high sequence homology in the cobra venom inhibitors. These findings strongly suggest that the cobra venom inhibitors as well as Russell's viper inhibitor II have very similar conformations to that established for BPTI.抄録全体を表示PDF形式でダウンロード (1304K) -
Hidetsune TAMAOKI, Fumio SAKIYAMA, Kozo NARITA1976 年 79 巻 3 号 p. 579-589
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーRibonuclease T1 [EC 3.1.4.8] was selectively hydrolyzed by digestion with trypsin at the peptide bond of the single arginine residue at position 77. Selective hydrolysis was achieved by blocking the s-amino group of Lys-41 with 2-methoxy-5-nitrotropone and subsequent digestion with trypsin in the presence of 2M urea.
The trypsin-digested ribonuclease T1 was composed of two polypeptide chains containing 77 and 27 residues, though the two chains were covalently linked by a disulfide bond between Cys-6 and Cys-103. The modified enzyme lost enzymatic activity toward RNA and the ability to bind to 3'-GMP. The circular dichroic spectrum of the modified protein suggested that its conformation was extensively destroyed.
It is concluded from the present results that the continuity of the peptide chain at the arginine residue is extremely important for maintaining the active conforma- tion of the enzyme protein and for the enzymatic function of ribonuclease T1.抄録全体を表示PDF形式でダウンロード (921K) -
Yuhei MORITA, Fumio YAGI, Shigeo AIBARA, Honami YAMASHITA1976 年 79 巻 3 号 p. 591-603
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーResearch Institute for Food Science, Kyoto UniversityThe molecular weight of soybean β-amylase [EC 3.2.1.2] was determined to be 57, 000 daltons by the sedimentation equilibrium method, and the enzyme was found to consist of 494 amino acid residues. No difference was found in molecular weight or composition between two components of β-amylase separated by ion-exchange chromatography. The N-terminus of the enzyme was not detectable by the fluorodinitrobenzene method or phenylisothiocyanate method, and the C-terminus was determined to be alanine by the carboxypeptidase [EC 3.4.12.2] method. Five half-cystine residues were found in the form of cysteine; all the sulfhydryl groups could be titrated by p-chloromercuribenzoate after denaturation of the enzyme with guanidine hydrochloride, but only some in the native enzyme. The rates of mercaptide formation of these groups were dependent on pH and were different from each other, all being much lower than the rate for the free sulfhydryl group in mercaptoethanol. Differential titration experiments at different pH's and in the presence of maltose showed that mercaptide formation by only one sulfhydryl group caused loss of activity, and the reaction was accompanied by changes in the environ- ment around aromatic side chains in the enzyme, which were detected by difference spectra and fluorescence emission spectra. These facts suggest that modification of the sulfhydryl groups causes a conformational change of the enzyme. Some pre-liminary crystallographic data for crystals formed at pH 4.0 were obtained, and inactivation by heavy metal salts was examined in relation to the preparation of isomorphous heavy atom derivatives.抄録全体を表示PDF形式でダウンロード (1639K) -
Masuyuki KATSUMATA, Allen S. GOLDMAN1976 年 79 巻 3 号 p. 605-611
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe substrate effect in enzyme reactions has been explained mostly in terms of an additional substrate binding site on the enzyme other than the catalytic site. A rate equation for the reaction is introduced according to the steady state mechanism as follows: v=(Ps3+Qs2+Rs)/(s3+Ls2+Ms+N), where the six parameters, L, M, N, P, Q, and R, can be determined by the least-squares method from the experimental points. The v vs. s curve has an asymptote parallel to the s abscissa, and can be classified into one of four types. The type A curve has an intersection with the asymptote and an apparent maximum velocity; the curve descends toward the asymptote. Type B has no intersection and no stationary point; the curve ascends toward the asymptote. Type C has two intersections and two stationary points, an apparent maximum velocity and a minimum velocity; the curve ascends toward the asymptote. Type D has no intersection and two stationary points; the curve ascends toward the asymptote. The equation was applied to the 3β-hydroxysteroid dehydro-genase [EC 1.1.1.145] reaction of rat testicular microsomes. The conversion of 3β-hydroxyandrost-5-ene-17-one was represented by type C, with an apparent maximum velocity of 0.338 nmole/min/mg protein at 0.912μM of the substrate concentration, minimum velocity of 0.108 nmole/min at 16.6μM, and saturating velocity of 0.169 nmole/min at infinite concentration of the substrate. The conversion of 3β-hydroxy-pregn-5-ene-20-one was of type B, having two inflexion points, 0.320 nmole/min at 2.735 pM and 0.814 nmole/min at 12.39μM, and a saturating velocity of 3.80 nmoles/ min at infinite concentration of the substrate.抄録全体を表示PDF形式でダウンロード (458K) -
Yoshihiro MIYAKE, Miho FUKUYAMA1976 年 79 巻 3 号 p. 613-620
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーOxygen-consuming reactions of cholesterol oxidase [EC 1.1.3.6] and microsomes were measured with a galvanic oxygen electrode which was attached to an offset amplifier for sensitive measurement of the reaction processes. The sensitivity of this oxygraphic method for detection of oxygen consumption was ten times greater than that of the usual method. The minimum rate of slow oxygen-consuming reactions which could be estimated was about 5 nmoles of oxygen per min, and the minimum amount of oxygen consumption which could be determined was also about 5 nmoles. An oxygraphic method for direct and rapid determination of cholesterol was demonstrated using one-twentieth the amount of cholesterol oxidase which is used for the colorimetric method. The processes of cyanide-suppressed β-NADH-dependent oxygen consumption and cyanide-insensitive α-NADH-dependent oxygen consumption, which were difficult to follow by the usual method, were followed using a small amount of microsomes (less than 1mg protein/ml). Furthermore, the temporary cessation of α-NADH-dependent oxygen consumption caused by ferricyanide and the corresponding oxidation-reduction of reduced cytochrome b5 were followed in the presence of ADP. ADP did not inhibit the oxygen consumption. The results indicate that the oxygen consumption with α-NADH is due to electron transfer from α-NADH via NADH-cytochrome b5 reductase and cytochrome b5, in which the rate-determining step lies at some reaction after the reduction of cytochrome b5.抄録全体を表示PDF形式でダウンロード (3537K) -
Kazuko SHIBATA-SEKIYA1976 年 79 巻 3 号 p. 621-623
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーLTV Difference spectra of H-meromyosin (HMM) during the steady state of the myosin-ATPase reaction [EC 3.6.1.3] were measured in 1.5 and 0.05M KCl in the presence of 5mM MgCl2 and 20mM Tris-HCI at pH 8.0 and 24°, using pyruvate kinase [EC 2.7.1.40] and phosphoenolpyruvate to regenerate ATP. It was found that the difference spectrum and its dependence on ATP concentration were the same in 1.5M KCl as in 0.05M KCl. On the bases of these and other results, the nature of the intermediates of HMM ATPase in the steady-state reaction of HMM ATPase was discussed.抄録全体を表示PDF形式でダウンロード (203K) -
Susumu ANDO, Kazuo KON, Miyoko ISOBE, Yoshitaka NAGAI, Tamio YAMAKAWA1976 年 79 巻 3 号 p. 625-632
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーA novel glycolipid containing N-acetylglucosamine (lacto-N-triose II ceramide, Amino CTH-I) was isolated as a minor component from the ceramide trihexoside fraction of human erythrocyte lipids. This glycolipid was purified by column chromatography and preparative high-speed liquid chromatography on latrobeads.
Its structure was found to be N-acetylglucosaminyl(β1-3)galactosyl(β1-4)glucosyl- (β1-1)ceramide, so it is suggested that it may be a precursor of paragloboside and blood group-active glycolipids.抄録全体を表示PDF形式でダウンロード (3344K) -
Kazunobu MATSUSHITA, Ikuzo URITANI1976 年 79 巻 3 号 p. 633-639
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーAn inhibitor of sweet potato acid invertase [EC 3. 2. 1. 26] was found in fresh sweet potato root tissue, and partially purified. The inhibitor is possibly a thermostable protein with a molecular weight of about 19, 500. The inhibitory activity is highly specific to acid invertase. The inhibitor binds to the enzyme' reversibly in a noncompetitive way, inhibiting the enzyme activity.抄録全体を表示PDF形式でダウンロード (479K) -
IV. Enzymatic Synthesis of 3-O-α-D-Glucopyranosyl-L-sorbose and 4-O-α-D-Glucopyranosyl-D-xylose Using Cyclodextrin GlycosyltransferaseSumio KITAHATA, Shigetaka OKADA1976 年 79 巻 3 号 p. 641-648
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe acceptor specificity of the transglycosylation reaction of cyclodextrin glycosyltransferase [EC 2.4.1.19] was investigated using various sugars and sugar alcohols. L-Sorbose, D-xylose, and D-galactose, which contain configurational or structural changes relative to the D-glucopyranose unit at positions other than position 1, were also shown to be efficient acceptors in the transglycosylation reaction of this enzyme. It was shown by chemical and enzymatic methods that this enzyme could transfer glycosyl residues only to the C3-hydroxyl group of L-sorbose and C4-hydroxyl group of D-xylose, producing oligosaccharides terminated by 3-O-α-D-glucopyranosyl-L-sorbose and 4-O-α-D-glucopyranosyl-D-xylose at the reducing ends, respectively.抄録全体を表示PDF形式でダウンロード (2580K) -
I. Binding of N-Ethylmaleimide to Sarcoplasmic Reticulum: Evidence for Sulfhydryl Groups in the Active Site of ATPase and for Conformational Changes Induced by Adenosine Tri- and DiphosphateHiromi YOSHIDA, Yuji TONOMURA1976 年 79 巻 3 号 p. 649-654
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe time course of binding of N-ethylmaleimide (NEM) to the SR was measured at pH 7.5 in the presence or absence of ATP or ADP. The following results were obtained.
1. Both in the presence and absence of nucleotide, the ATPase [EC 3.6.1. 3] activity decreased linearly with increase in the amount of NEM bound to the fragmented sarcoplasmic reticulum (SR), and was inhibited almost completely by the binding of 2 moles of NEM per 105g of the SR protein.
2. The amount of NEM incorporated into the ATPase (M. W.=105, 000) was measured by SDS disc-gel electrophoresis. It was shown that the ATPase activity was inhibited almost completely by the binding of 2 moles of NEM per mole of ATPase.
3. The rate of binding of NEM to SR decreased by 30-40% in the presence of either ATP or ADP. The concentrations of both ATP and ADP for half-saturation were 0.1-0.2mM.
4. The effect of nucleotide on the rate of binding of NEM was not changed by the presence of Ca2+ and Mg2+ ions. Similar effects were also observed even when the SR membranes were solubilized with Triton X-100.
It is suggested from these results that one or two SH groups are located in the active site of the SR ATPase, and that conformational changes are induced by the addition of ATP and ADP.抄録全体を表示PDF形式でダウンロード (431K) -
Tateo YAMANAKA1976 年 79 巻 3 号 p. 655-660
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe subunits of cytochrome c-553 (Chlorobium thiosulfatophilum) were studied. The cytochrome is split into a cytochrome moiety and a flavoprotein moiety by treatment with 2% trichloroacetic acid. The molecular weights of the cytochrome and flavo-protein moieties are 11, 000 and 47, 000, respectively. The cytochrome moiety seems to have only one cysteine residue in the molecule, although its heme appears to be quite similar to the usual heme c. The flavoprotein moiety shows absorption peaks at 350 and 452nm and is insoluble at neutral pH. When the two moieties are mixed at alkaline pH, and the pH of the mixture is then brought to neutral, the flavoprotein moiety remains soluble. However, the preparation thus obtained is different from the original cytochrome c-553.抄録全体を表示PDF形式でダウンロード (450K) -
Properties of Purified Hydrogenase from the Particulate Fraction of Desulfovibrio vulgaris, MiyazakiTatsuhiko YAGI, Keisaku KIMURA, Hidehiro DAIDOJI, Fumiko SAKAI, Shohei ...1976 年 79 巻 3 号 p. 661-671
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe properties of purified hydrogenase [EC 1.12.2.1] solubilized from particulate fraction of sonicated Desulfovibrio vulgaris cells are described. The enzyme was a brownish iron-sulfur protein of molecular weight 89, 000, composed of two different subunits (mol. wt.: 28, 000 and 59, 000), and it contained 7-9 iron atoms and 7-8 labile sulfide ions. Molybdenum was not detected in the preparation. The absorption spectrum of the enzyme was characteristic of iron-sulfur proteins. The milli-molar absorbance coefficients of the enzyme were about 164 at 280nm, and 47 at 400nm. The absorption spectrum of the enzyme in the visible region changed upon incubating the enzyme under H2 in the presence of cytochrome c3, but not in its absence. This spectral change was due to the reduction of the enzyme. The absorbance ratio at 400nm of the reduced and the oxidized forms of the enzyme was 0.66.
The activity of the enzyme was hardly affected by metal-complexing agents such as cyanide, azide, 1, 10-phenanthroline, etc., except for CO, which was a strong inhibitor of the enzyme. The activity was inhibited by SH-reagents such as p-chloromercuribenzenesulfonate. The enzyme was significantly resistant to urea, but susceptible to sodium dodecyl sulfate. These properties were very similar to those of clostridial hydrogenase [EC 1.12.7.1], in spite of differences in the acceptor specificity and subunit structure.抄録全体を表示PDF形式でダウンロード (2186K) -
I. Physicochemical PropertiesKazutaka MIYATAKE, Yoshihisa NAKANO, Shozaburo KITAOKA1976 年 79 巻 3 号 p. 673-678
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーUsing a new apparatus for preparative polyacrylamide gel electrophoresis, panto-thenate synthetase (D-pantoate: β-alanine ligase (AMP-forming), [EC 6.3.2.1] was purified about 500-fold from Escherichia coli B. It was found to be homogeneous in analytical disc gel electrophoresis and sedimentation ultracentrifugation (s020, 9w=4.9).
From sedimentation equilibrium ultracentrifugation, a molecular weight of 70, 100 was obtained, which is in good agreement with the value obtained by the Sephadex G-150 gel filtration method (69, 000); the diffusion constant was calculated to be 5.88×10-7cm2/sec. The minimum molecular weight calculated from the amino acid composition of this enzyme protein was 19, 700, a value in reasonable accord with molecular weight of the enzyme subunit, 18, 000, obtained by gel electrophoresis in the presence of sodium dodecylsulfate. The partial specific volume, _??_was calculated to be 0.71cm3/g. The enzyme had an amino-terminal glycyl residue and a Leu-Ala-Ser-OH sequence at the carboxyl end. Electrophoresis of the enzyme with carrier ampholine gave an isoelectric point of pH 4.6.抄録全体を表示PDF形式でダウンロード (1487K) -
Atsushi IKAI1976 年 79 巻 3 号 p. 679-688
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe structure of human serum low density lipoprotein (LDL) was investigated by perturbing the LDL structure with sodium dodecyl sulfate (SDS). The change in LDL structure induced by the addition of SDS was monitored by sedimentation velocity measurements, ultraviolet difference spectroscopy, fluorescence spectroscopy and proteolytic digestion of apo-LDL with subtilisin BPN' [EC 3.4.21.14]. As the concentration of SDS was increased from 0.1mg/ml to 3mg/ml with LDL concentra-tions between 2.0mg/ml and 4.4mg/ml, the sedimentation coefficient of LDL changed in three distinct steps. It was found by chemical analyses that not more than 30% of the total lipid was lost from LDL in the second step, whereas the final step in the change of sedimentation coefficient corresponded to the complete removal of apo-LDL from the constituent lipids of LDL. The ultraviolet difference spectrum between the native and SDS-treated LDL and the quenching of LDL fluorescence underwent about 80% of the total change while the SDS concentration was only sufficient to cause the second of the three step changes in sedimentation coefficient. 'SDS-polyacrylamide gel electrophoresis of apo-LDL treated with subtilisin BPN' also showed that more than 70% of apo-LDL became susceptible to proteolysis under the same conditions.
These results were interpreted as indicating that the solubilization of 20 to 30%0 of the lipids on the surface of LDL exposed nearly 80% or more of apo-LDL to the solvent. A small portion of apo-LDL was, however, still firmly anchored to the remaining lipid micelle as long as the concentration of SDS was less than that re-quired to cause the final step of the change in sedimentation coefficient.抄録全体を表示PDF形式でダウンロード (2736K) -
Takayoshi IIO, Koshin MIHASHI, Hiroshi KONDO1976 年 79 巻 3 号 p. 689-691
発行日: 1976/03/25
公開日: 2008/11/18
ジャーナル フリーThe kinetics of conformational change of troponin C (TN-C) induced by binding and removal of calcium ions were studied by measuring the fluorescence of tyrosine by stopped-flow spectrofluorometry. When the concentration of free calcium ions in the solution [Ca2+] was increased rapidly from 4× 10-9 M to 1×10-3M at neutral pH, a first-order reaction with a rate constant of 13.7 sec-1, which was preceded by a much faster reaction, was observed. In contrast, when [Ca2+] was reduced from 2×10-3M to 4.4×10-8M, two first-order reactions with rate constants of 7.4 and 0.78 sec-1, preceded by a much faster reaction, were observed.抄録全体を表示PDF形式でダウンロード (1108K)
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