巻号一覧
85 巻, 4 号
選択された号の論文の27件中1～27を表示しています
- |<
- <
- 1
- >
- >|
-
Tadayoshi IMAI1979 年 85 巻 4 号 p. 887-899
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーA glycohydrolase that catalyzes the irreversible conversion of NMN to nicotinamide and ribose 5-phosphate has been partially purified from a sonic extract of Azotobacter vinelandii. The enzyme is highly specific for NMN. NAD, NADP, nicotinic acid-adenine dinucleotide, nicotinamide riboside, and α-NMN are not significantly hydrolyzed by this enzyme, nor do they compete with NMN. The enzyme also exhibits an absolute dependence on guanylic acid derivatives with the following order of relative effectiveness: GTP, guanosine 5'-tetraphos-phate>dGTP, GDP, 2'-GMP, 3'-GMP>GMP, dGMP. A heat-resistant, nondialyzable factor which could replace the GTP requirement was found in the sonic extract. The KA for GTP and the Km for NMN in the presence of GTP at 1mM were calculated to be 0.025mM and 4.5mM, respectively. GMP, dGMP, and dCMP were found to be effective inhibitors of the enzyme when 1mM GTP was also present. The kinetic data suggest that the binding site for these mononucleotides is distinct from the active site or the GTP binding site.
The ability of this enzyme to cleave NMN is suggestive of a metabolic role of the enzyme in selective conversion of NMN to nicotinamide, which, in turn, would be re-utilized by the cell as a precursor of NAD via nicotinic acid.抄録全体を表示PDF形式でダウンロード (964K) -
Katsuyuki TANIZAWA, Kenji SODA1979 年 85 巻 4 号 p. 901-906
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーKynureninase [L-kynurenine hydrolase, EC 3. 7. 1. 3] was purified from pig liver by a procedure including DEAE-cellulose chromatography, hydroxyapatite chromatography, ammonium sulfate fractionation, DEAE-Bio Gel chromatography, Sephacryl S-200 gel filtration, kynure-nine-Sepharose affinity chromatography, and Sephadex G-200 gel filtration. The enzyme was found to be homogeneous by the criterion of disc-gel electrophoresis. The enzyme has a molecular weight of about 100, 000 and exhibits absorption maxima at 280 and 420nm. The optimum pH and the isoelectric point of the enzyme are 8.5 and 5.0, respectively. The Michaelis constants were determined to be as follows: L-kynurenine, 7.7×10-4M; L-3-hydroxy-kynurenine, 1.3×10-5M; and pyridoxal 5'-phosphate, 1.8×10-6M. L-3-Hydroxykynurenine is hydrolyzed more rapidly than L-kynurenine; the liver enzyme can be regarded as a 3-hydroxy-kynureninase.抄録全体を表示PDF形式でダウンロード (996K) -
Chemical Composition and Binding to Glycogen of UDP-Glucose: Glycogen 4-α-GlucosyltransferaseHidenari TAKAHARA, Kazuo MATSUDA1979 年 85 巻 4 号 p. 907-914
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーHomogeneous glycogen synthase [UDP-glucose: glycogen 4-α-glucosyltransferase, EC 2. 4. 1. 11], glucose-6-P-dependent form, from Neurospora crassa was prepared by the procedure described in the previous report ((1978) Biochim. Biophys. Acta 522, 363-374). About 10mg of protein could be obtained from 850g of the mycelia (wet weight). The glycogen synthase sedimented as one major (12.5S) and three minor components, all of which were enzymatically active. The 12.5S component was found to be a trimer of the subunit (Mw. 88, 000-90, 000) and the other minor components were the tetramer, dimer, and monomer.
The purified enzyme was shown to contain no appreciable amount of carbohydrate. The amino acid composition was determined and histidine was found as the NH2-terminal amino acid by the dansyl method.
The activation patterns of the activator glucose-6-P toward either substrate, UDP-glucose or glycogen, were determined. On the basis of the results, the attachment of glucose-6-P is a necessary prerequisite for the addition of glycogen to the catalytic site of the synthase. On the other hand, the activator did not affect the binding capacity of the synthase toward glycogen. These results are therefore suggestive of the existence of a glycogen storage site in the glycogen synthase molecule.抄録全体を表示PDF形式でダウンロード (1169K) -
Katsuhide YUTANI, Kyoko OGASAHARA, Minoru SUZUKI, Yoshinobu ZUGINO1979 年 85 巻 4 号 p. 915-921
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーIn order to elucidate the roles of individual amino acid residues in the conformational stability of proteins, the denaturation by guanidine hydrochloride of the wild-type tryptophan synthase α-subunit of Escherichia coli and two mutant proteins, trpA33 (Glu49→Met) and trpA11 (G1u49→Gln), has been compared by means of CD measurements at pH 7.0 and various temperatures. CD spectra of the two mutant proteins were similar to that of the wild-type protein. The trpA33 and the trpA11 proteins were more and less resistant, respectively, to guanidine hydrochloride than the wild-type protein at 9.7 to 49.6°C. The free energy change of unfolding in water, ΔGH2Ond, was evaluated assuming a three state denaturation, since the denaturation curves of the three proteins suggested the presence of one stable intermediate. The values of ΔGH2Ond for the trpA33, the wild-type, and the trpA11 proteins at 25.8°C and pH 7.0 were 13.4, 8.8, and 6.3 kcal/mol, respectively. The ΔGH2Ond of the trpA11 protein was almost independent of temperature, though that of the trpA33 protein was remarkably dependent on temperature. The conformational stabilities of the three proteins were correlated with the hydrophobicities of the substituted amino acid residues.抄録全体を表示PDF形式でダウンロード (532K) -
Hirokazu KOBAYASHI, Tetsuko TAKABE, Mikio NISHIMURA, Takashi AKAZAWA1979 年 85 巻 4 号 p. 923-930
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーSpinach leaf ribulose-1, 5-bisphosphate (RuP2) carboxylase, which normally has a quaternary structure composed of eight large subunit (A) and eight small ones (B), was activated by CO2 and Mg2+ when subunit B was depleted. RuP2 carboxylase isolated from the purple non-sulfur photosynthetic bacterium, Rhodospirillum rubrum, which was reported to be a dimer of subunit A, was also activated by these activators. In the catalytic process of the enzyme reaction after activation by CO2 and Mg2+, spinach RuP2 carboxylase lacking subunit B or the enzyme treated with anti-subunit B serum (anti-[B]), exhibited a higher Km(CO2) value than the carboxylase which had been reconstituted or treated with non-immunized control serum. R. rubrum RuP2 carboxylase also showed a much higher Km(CO2) value than the native spinach enzyme. In the activation process, anti-[B]-treated spinach RuP2 carboxylase exhibited a lower degree of activation by CO2 or Mg2+ than the control serum-treated enzyme, although equilibrium constants for CO2 and Mg2+ did not change. No interaction between subunit B and CO2 molecules was observed by a fluorometric study with 2-p-toluidinonaphthalene-6-sulfonate. R. rubrum RuP2 carboxylase, like spinach carboxylase, was activated by NADPH or 6-P-gluconate. R. rubrum RuP2 carboxylase/oxygenase possessed properties basically similar to those of the spinach enzyme. Our results thus lead to the tentative conclusion that subunit A is primarily responsible for the enzyme activation and catalysis, and that subunit B is involved in sustaining the conformation of the enzyme molecule which is necessary for effective activation.抄録全体を表示PDF形式でダウンロード (628K) -
Binding Aspects and Spectral Properties of D-Amino Acid Oxidase and Riboflavin Binding ProteinKiyoshi SHIGA, Kihachiro HORIIKE, Yasuzo NISHINA, Shohei OTANI, Hirosh ...1979 年 85 巻 4 号 p. 931-941
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーTo study flavin-protein and flavoprotein-ligand interaction, the absorption, CD and MCD spectra of riboflavin, FAD, roseoflavin, the complexes of riboflavin and roseoflavin with riboflavin binding protein (RBP), D-amino acid oxidase (o-AO) and its complexes with ligands were observed in the spectral region of 310-600nm and the binding properties of D-AO with di-substituted benzoate derivatives and of RBP with roseoflavin were also measured.
The dimer of D-amino acid oxidase has a higher affinity for di-substituted benzoate derivatives than the monomer. The change in the absorption of FAD in D-AO caused by the binding of the first ligand to the dimer, which can bind two ligands, was similar to that caused by the binding of the second ligand.
Roseoflavin could bind to RBP in a 1:1 ratio and the dissociation constant was 3.8×10-8M. The protein fluorescence of RBP was quenched by about 86% due to complex formation with roseoflavin.
The MCD spectra showed similar patterns for all molecular complexes of riboflavin and FAD, with two negative extrema of ellipticity which probably correspond to the Faraday B-term, but the Faraday A-term could not be observed, suggesting that there was no degeneracy in the excited state of flavins. It is suggested that the magnitude of the ellipticity in MCD spectra around 370nm reflects the interaction of isoalloxazine with the aromatic ring instead of with the ribityl group. The CD spectra of these complexes displayed wider variation. This showed that the pattern of the CD spectra more sensitively reflected the environment around isoalloxazine than did that of the MCD spectra.
It is also suggested, based on a comparison of the absorption, CD and MCD spectra, that the vibronic structure of flavin was modified differently by each flavin-protein or flavoproteinligand interaction.抄録全体を表示PDF形式でダウンロード (818K) -
Tomofusa TSUCHIYA, Keiko TAKEDA1979 年 85 巻 4 号 p. 943-951
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThe cation/H+ antiport reaction was studied in Escherichia coli. 45Ca2+ transport in isolated membrane vesicles was previously shown to be energized by an artificially imposed H+ gradient (Tsuchiya, T. and Rosen, B. P. (1976) J. Biol. Chem. 251, 962-967). That observation suggested an antiport mechanism for Ca2+/H+ exchange. To evaluate this possibility we tested Ca2+-induced H+ flux by measuring the fluorescence change of 9-aminoacridine and by monitoring the change of pH. Upon supply of a respiratory substrate, generation of a large pH gradient (interior-acidic) was observed in everted membrane vesicles. The addition of Ca2+ to respiring vesicles caused a partial collapse of the pH gradient, indicating that Ca2+ induced an H+ efflux. The addition of Ca2+ to an anaerobic cell suspension induced an acidification of the medium (efflux of H+). These findings strongly support a Ca2+/H+ antiport mechanism in Escherichia coll. Similar results were obtained for Na+/H+ exchange. The Ca2+/H+ antiport reaction seemed to be an electrogenic process, transferring positive charge with Ca2+ movement, while the Na+/H+ antiport reaction seemed to be an electroneutral process. Sr2+ inhibited the Ca2+/H+ antiport. Phosphate had no significant effect on the Ca2+/H+ antiport process, although phosphate greatly stimulated the accumulation of 45Ca2+ in the vesicles when energized either by respiration (or ATP hydrolysis) or by an artificial H+ gradient.抄録全体を表示PDF形式でダウンロード (656K) -
Tamio NOGUCHI, Yoshiyuki ARAMAKI, Takaaki KAMEJI, Shin-ichi HAYASHI1979 年 85 巻 4 号 p. 953-959
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーIn rats fed ad libitum, a marked circadian rhythm with a peak at night was observed in the hepatic level of ornithine decarboxylase (ODC) [EC 4. 1. 1. 17], the enzyme for the first step of polyamine synthesis. A similar rhythm was found in the hepatic content of putrescine, but not of spermidine or spermine. The mitotic activity of the liver also exhibited a clear rhythm with a peak in the daytime. The rhythms of both ODC and mitosis were generated by cyclic ingestion of proteinous food, since the peaks shifted when rats were meal-fed and both activities disappeared on starvation or protein deprivation. The close parallel between the rhythms suggested that synthesis of polyamine, especially that of putrescine, was a prerequisite for the rhythmic growth of liver.
The dietary induction of hepatic ODC depended on the nutritive value of dietary protein; zein or gelatin was effective only when supplemented with limiting amino acids and there was a good correlation between the hepatic ODC level and the relative growth rate.抄録全体を表示PDF形式でダウンロード (486K) -
Sachio GOTO, George P. HESS1979 年 85 巻 4 号 p. 961-965
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThe enhancement of fluorescence intensity of the dansyl group due to the formation of trypsinor trypsinogen-dansyl-L-arginine complex was measured. Dansyl-L-arginine (L-DA) is a product in the trypsin-catalyzed hydrolysis of dansyl-L-arginine methylester. Trypsinogen was found to have only one binding site for L-DA with the dissociation constant of 6.9×10-3M, which is identical with the Michaelis constant for the trypsin-catalyzed hydrolysis of dansyl-L-arginine amide (Goto, S. and Hess, G.P., unpublished results). This finding and the results of X-ray diffraction studies (1, 2) suggest that this binding site is located in the active site of the enzyme. On the other hand, the active enzyme, trypsin, was found to have at least two binding sites for L-DA. One is located in the active site. The dissociation constant for L-DA bound to this site is 6.7×10-3M. The other site is probably located in the allosteric site of trypsin. The dissociation constant for L-DA bound to this site is 4.8×10-4M.抄録全体を表示PDF形式でダウンロード (375K) -
Asao MAKIOKA, Tamio HIRABAYASHI1979 年 85 巻 4 号 p. 967-975
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリー1. A troponin C-like protein was prepared from frozen chicken gizzard by preparative polyacrylamide gel electrophoresis and its apparent molecular weight was estimated to be about 15, 500 daltons.
2. In urea gel electrophoresis, the mobility of the troponin C-like protein increased slightly in the presence of Ca2+, like that of skeletal muscle troponin C. On the other hand, the mobility of the troponin C-like protein in glycerol gel electrophoresis, unlike that of skeletal muscle troponin C, was significantly decreased by Call.
3. In alkaline gel electrophoresis, the troponin C-like protein formed a Ca2+-dependent complex with troponin I or troponin T from skeletal muscle.
4. The troponin C-like protein could neutralize the inhibitory effect of skeletal muscle troponin I on the Mg2+-activated ATPase of actomyosin from rabbit skeletal muscle, but could not confer Ca2+-sensitivity on the actomyosin in the presence of troponin I and troponin T from skeletal muscle.抄録全体を表示PDF形式でダウンロード (4097K) -
Morphology and Activity Modified with Sulfhydryl ReagentsTsunemi HASEGAWA, Kazuyuki TERAYAMA, Masao AZEGAMI, Shin-ichi ISHII1979 年 85 巻 4 号 p. 977-988
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーElectron microscopic observation of pyocin Rl with the negative staining technique demonstrated that pyocin Rl retained its phage tail-like shape of an extended sheath even when it was inactivated by treatment with p-chloromercuribenzoic acid (PCMB) or 4-(p-sulfophenyl-azo)-2-mercuriphenol (SAMP). Thus it was shown that the contraction and extension of the sheath does not occur reversibly on the modification of sulfhydryl groups accompanying the change of activity. The activity lost under these conditions was restored to the original level by treatment with 2-mercaptoethanol (2-ME).
Numbers of sulfhydryl groups in the pyocin R1 particle were determined to be 208 mol and 152 mot per mol (11.8×106 daltons) by spectrophotometric titration with SAMP and by membrane-filter assay with radioactive PCMB, respectively. Most of these cysteine residues appeared to be localized in the substructure other than the sheath and core.
It was also shown that all of these sulfhydryl groups were not necessary for expression of its activity but a part of them were essential for adsorption to the sensitive cells.抄録全体を表示PDF形式でダウンロード (3141K) -
I. Application to GlycoproteinsSumihiro HASE, Tokuji IKENAKA, Yoshio MATSUSHIMA1979 年 85 巻 4 号 p. 989-994
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThe reducing end sugar of an oligosaccharide and 2-aminopyridine were linked by means of reductive amination with sodium cyanoborohydride. The fluorescent derivative of the oligosaccharide thus obtained, which had a positive charge, was subjected to two-dimensional paper electrophoresis. In the first direction, the sugar derivative moved according to its degree of polymerization, and in the second direction, it moved according to the structure of the borate complex. In this way fluorescent derivatives of saccharides were mapped on a sheet of paper. The method was applied to some known mono- and oligosaccharides and to the saccharides obtained by nitrous deamination of the oligosaccharide portions of glycoproteins (fetuin, Taka-amylase A, and ovalbumin). The fingerprints thus obtained were characteristic of the chemical structures of the original oligosaccharides.抄録全体を表示PDF形式でダウンロード (1648K) -
II. Linkage Point AnalysesSumihiro HASE, Tokuji IKENAKA, Yoshio MATSUSHIMA1979 年 85 巻 4 号 p. 995-1002
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThe fluorescent oligosaccharide derivative having a positive charge described in the preceding paper (Hale et al. (1979) J. Biochem. 85, 217-220) was shown to be useful for the purpose of determining the sequence and the linkage points of the sugar units. In the sequence analyses of an oligosaccharide, the 2-aminopyridine derivative was partially hydrolyzed. The 2-amino-pyridine derivatives in the hydrolysates were separated by paper electrophoresis (pH 5.0). Each derivative (a monosaccharide derivative to an oligosaccharide derivative) was eluted and the component sugars were analyzed by TLC. In order to determine the linkage points, 2-aminopyridine derivative of an oligosaccharide was permethylated and then partially hydrol-yzed. Newly produced hydroxyl groups were methylated with [2H3]methyliodide. The neutral and basic components were separated by passage through a Dowex 50 (H+) column, the fluorescent components having [2H3]methyl groups were separated by TLC, and each was eluted and hydrolyzed. The hydrolysates were converted into alditol acetates. The linkage points of the sugars were judged by determining the position of [2H3]methyl groups in the tetramethyl alditol acetates by gas chromatography-mass spectrometry. The method, which requires no quantitative manipulation, was applied to some known oligosaccharides, lacto-N-tetraose, a tetrasaccharide isolated from a glycoprotein (fetuin), and maltotriose.抄録全体を表示PDF形式でダウンロード (1152K) -
Kihachiro UEHARA, Shigeyasu MANNEN, Saburo HOSOMI1979 年 85 巻 4 号 p. 1003-1008
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーUpon addition of NADP+, the rose bengal-sensitized photoinactivation of D-erythrulose reductase from beef liver is prevented to a remarkable extent. Adenosine 2', 5'-diphosphate (2', 5'-ADP) also has a protective effect, but to a lesser extent. On the other hand, 2'-AMP markedly enhances the photoinactivation. Other nucleotides which have no 2'-phosphoryl group, such as NAD+, 3'-AMP, 5'-AMP, ADP, and NMN, are ineffective. Further, only 2'-AMP derivatives (NADP+, 2', 5'-ADP, and 2'-AMP) among these nucleotides were found to be potent competitive inhibitors of the enzyme with small K1's (6-13 μ1M). Photooxidation of some methionine residues in the enzyme is prevented by the addition of NADP+ and accel-erated in the presence of 2'-AMP. Photooxidation product(s) of 2'-AMP derivatives have no effect upon the enzymatic activity. Although NADP+ and 2'-AMP induce detectable con-formational changes of the enzyme, the changes are not characteristic to the compounds. Based on these observations, we present a possible action mechanism of 2'-AMP derivatives on the photoinactivation of D-erythrulose reductase.抄録全体を表示PDF形式でダウンロード (441K) -
I. Properties and Distribution of Thyroglobulin Labeled with Radioiodine in Pig Thyroid SlicesShigeru MATSUKAWA, Toichiro HOSOYA1979 年 85 巻 4 号 p. 1009-1021
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーPig thyroid slices were incubated with Na131I and the 17-19S 131I-labeled -thyroglobulin iso-lated was subjected to dissociation with 0.3 mM sodium dodecyl sulphate (SDS) on sucrose density gradient centrifugation and to iodoamino acid analysis. During the incubation, ini-tially dissociable thyroglobulin was gradually altered to 0.3mM SDS-resistant species with increasing incorporation of iodine. Microsome-bound, poorly iodinated thyroglobulin and preformed thyroglobulin were chemically iodinated and then subjected to analysis of disso-ciability and iodoamino acid contents with newly incorporated iodine. The results indicated that the behavior of the former thyroglobulin resembled that of 131I-thyroglobulin obtained from the slices. Then, thyroid slices were incubated for 3min with Na131I and 3H-leucine with or without 10-min chase incubation. The sucrose density gradient centrifugation patterns of 131I and 3H-radioactivity of cytoplasmic extracts indicated that 131I-thyroglobulin is contained in particulates, especially in vesicles with low density (d=1.12) and that some of them are released into the soluble fraction within 10min. The vesicles contained peroxidase and NADH-cytochrome c reductase, and are probably exocytotic vesicles in the apical area of cytoplasm of follicular cells. No positive evidence was obtained that plasma membranes participate in the iodination of thyroglobulin under the present experimental conditions.
These results suggest that, in the incubation of thyroid slices, iodine atoms are preferen-tially incorporated into newly synthesized, less iodinated thyroglobulin, rather than preformed thyroglobulin, and that the iodination occurs, at least to a certain degree, in apical vesicles before the thyroglobulin is secreted into the colloid lumen.抄録全体を表示PDF形式でダウンロード (1032K) -
Yoki MORI, Masahiko KOKETSU, Nobuhito ABE, Jiro KOYAMA1979 年 85 巻 4 号 p. 1023-1028
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーC_??_r, an activated subcomponent of the first component of the complement system, was highly purified from rabbit serum by affinity chromatography on IgG-Sepharose 6B followed by column chromatography on CM-Sephadex C-50. The C_??_r thus purified had a molecular weight of 105, 000, consisting of two polypeptide chains connected by disulfide bonds; the molecular weights of the chains were 60, 000 and 45, 000. The C_??_r was found to reconstitute C_??_complex when it reacted with rabbit Clq and C_??_s in the presence of Ca2+, since C_??_s was able to bind to Clq bound on sensitized sheep erythrocytes only in the presence of C_??_r. On the other hand, an active C_??_s fragment derived by hydrolysis of the H chain without any loss of C_??_s activity [J. Biochem. 80, 1423-1427 (1976)] could not bind to Clq even in the presence of C_??_r. This result indicates that a part of the H chain of C_??_s not contributing to the struc-tural integrity of an active site may be involved in the binding of C_??_s to C_??_r.抄録全体を表示PDF形式でダウンロード (988K) -
Mohammad Abul QASIM, Ahmad SALAHUDDIN1979 年 85 巻 4 号 p. 1029-1035
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーAmino groups of ovalbumin were modified with maleic anhydride and thereby 35% and 64% maleylated ovalbumins were obtained. As indicated by electrophoresis on polyacrylamide gels, the preparations were each homogeneous with respect to modification. Solvent perturbation experiments with ethylene glycol and dimethyl sulfoxide showed that 6 tyrosine and 1.5 tryptophan residues were exposed in 64% maleylated ovalbumin as against 3 tyrosine and 0.5 tryptophan residues in the native protein. Gel filtration results indicated a significant increase in the Stokes radius of ovalbumin upon chemical modification. The Stokes radius increased from 2.7nm in the native state to 3.3nm in 64% maleylated ovalbumin; the Stokes radius of the 35% maleylated ovalbumin was determined to be 3.1 nm. The intrinsic vis-cosities of native, 35% maleylated, and 64% maleylated ovalbumins were measured to be 3.9ml/g, 4.9ml/g, and 7.3ml/g, respectively. These results conclusively demonstrate disruption of the native conformation of ovalbumin upon maleylation of its amino groups. The loss of native conformation in modified ovalbumins was also revealed by a substantial decrease in immunological activity of the modified ovalbumins (90% of the native immunological activity in 35% maleylated and 40% in 64% maleylated ovalbumins). However, both hydro-dynamic and immunological results showed that the protein retains considerable native struc-ture even upon maleylation of 13 lysine residues.抄録全体を表示PDF形式でダウンロード (1154K) -
Fumiya OBATA, Rume SAKAI, Hiroyuki SHIOKAWA1979 年 85 巻 4 号 p. 1037-1045
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーConcanavalin A (Con A), the second fraction (P-II) obtained from the affinity chromatography of whole Con A, was further fractionated into three major fractions F1, F2, and F3 by CM-cellulose chromatography after the treatment with EDTA (Obata, F. et al. (1978) J. Biochem. 84, 103-109). The contents of Ca2+ and Mn2+ ions in these fractions were determined by atomic absorption measurement after the removal of free metal ions by gel filtration. The number of Ca2+ and Mn2+ ions bound to Con A was estimated with the assumption that Con A is a tetramer. The number of Ca2+ and Mn2+ ions was essentially integral for all the prepa-rations. P-II had 4.0 Ca2+ and 2.0 Mn2+ ions. This is represented as P-II (Ca: 4.0, Mn: 2.0). F3, F3 (Ca: 4.0, Mn: 1.8), had almost the same number of the metal ions as P-II. F2, F2 (Ca: 2.0, Mn: 0.8), contained about half as many ions of each metal as F3; and Fl, F1 (Ca: 0.2, Mn: 0.1), contained almost no metal ions. Fully metalized Con A, P-IIM or P-IIM (Ca: 4.1, Mn: 4.0), was prepared by incubation of P-II with excess amounts of Ca2+ and Mn2+ ions. This Con A preparation was subjected to CM-cellulose chromatography under the same conditions as P-II after the treatment with EDTA. P-IIM gave fundamentally the same chromatogram as P-II. The numbers of binding metal ions in P-11m and its three major frac-tions were consistent with those described above in P-Il and its three major fractions except that the number of Mn2+ ions in each fraction of P-IIM was double that in the corresponding fraction of P-II. CM-cellulose chromatography of the two starting materials revealed that the number of Ca2+ ions, but not Mn2+ ions, bound to Con A influences the electric charge of the protein in the ion-exchange chromatography.
The precipitation activity of all the Con A preparations toward glycogen was also estimated by using glycogen labeled covalently with Remazolbrilliant Blue R. The activity was affected mostly by the number of Ca2+ ions in Con A and slightly by the number of Mn2+ ions.抄録全体を表示PDF形式でダウンロード (725K) -
Hiroshi KIMURA, Noriko TAKAHASHI, Hisae MURATA, Heima UEMATSU1979 年 85 巻 4 号 p. 1047-1051
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーp-Chloromercuribenzoate-treated hemoglobin was digested by trypsin. The hydrolysate was subjected to gel-filtration on Bio-Gel P-4 and Sephadex G-50 columns, ion-exchange chro-matography on CM-Sephadex and DE 52 columns, and paper electrophoresis. Peptides obtained by this procedure were analyzed for amino acid compositions and amino-terminal amino acid sequences. The results showed that p-chloromercuribenzoate-treated hemoglobin was hydrolyzed to a limited extent by trypsin at the bonds involving the carboxyl group of a lysine or arginine residue in planes A-E in the parent hemoglobin, which represent the external region of the parent tetramer.
It is concluded therefore that the slight modification of hemoglobin enhances the sus-ceptibility of the protein to proteases and that the hydrolysis of the modified protein is limited.抄録全体を表示PDF形式でダウンロード (332K) -
Kuni TAKAHASHI, Mamoru ISEMURA, Tokuji IKENAKA1979 年 85 巻 4 号 p. 1053-1060
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThree distinct forms of cathepsin B [EC 3. 4. 22. 1] were purified from porcine liver by DEAE-cellulose chromatography, gel-filtration on Sephadex G-75, and CM-cellulose chromatography. These forms had different isoelectric points, pH 5.2 (Form I), pH 5.4 (Form II), and pH 5.8 (Form III). SDS-polyacrylamide gel electrophoresis gave a single band of a molecular weight of 29, 000 for Form III, while Form I and Form II gave three bands corresponding to molecular weights of 29, 000, 25, 000, and about 4, 000. N-Terminal amino acid analyses suggested that the small peptide chain of a molecular weight of ca. 4, 000 was derived and dissociated from the N-terminal site of the chain with a molecular weight of 29, 000. The dissociation was observed to a greater extent in Form I than in Form II. The association of these chains by disulfide bonds was ruled out, since the dissociation was achieved without any treatment by reducing agents. The amino acid compositions of the three forms were very similar. These forms had the same specific activity when BAPA was used as a substrate, but Form I showed much higher aldolase inactivating activity than Form III. These results suggest that Form III is the primary form of cathepsin B which consists of a single polypeptide chain, and that Form I and Form II are produced by in vivo processing of Form III.抄録全体を表示PDF形式でダウンロード (1543K) -
Ken OKABAYASHI, Eizo NAKANO1979 年 85 巻 4 号 p. 1061-1066
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーCitrate synthase [EC 4. 1. 3. 7] was purified from sea urchin eggs about 14-fold with a 23% yield, based on the activity of the crude extract. The molecular weight of the enzyme was about 100, 000 as determined by gel filtration. The optimum pH was about 7.8 in 100mM Tris-HCI. The apparent Km values for acetyl-CoA and for oxaloacetate were 33 and 3.2 μm, respectively. Monovalent and divalent cations inhibited the enzyme. lodoacetamide, pCMB, EDTA, NaF, and dithiothreitol did not affect the enzyme activity.
Oxaloacetate protected the enzyme against heat denaturation. Among nucleotides, ATP was the most potent inhibitor of the enzyme. The inhibition by ATP was competitive with respect to acetyl-CoA and mixed with respect to oxaloacetate.抄録全体を表示PDF形式でダウンロード (379K) -
Tatsuhiko FUTAMI, Noboru OTOTANI, Yasuko NAGATSUKA, Zensaku YOSIZAWA1979 年 85 巻 4 号 p. 1067-1073
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーCarbohydrate-containing substances were extracted from non-calcified (NCC) and calcified (CC) portions of bovine costal cartilage with 0.5M LaCl3 by the method of Mason and his co-workers, followed by dilution of the extract with 9 volumes of water. The precipitate formed on dilution yielded Fr. P, while Fr. S was obtained from the supernatant. Fr. P was separated into two subfractions by gel filtration on Sepharose 2B. The experimental results showed that Fr. P contained proteoglycans with different molecular sizes and compositions, while Fr. S contained proteoglycan, hyaluronic acid, glycoproteins, and glycogen. The present data suggest that in the proteoglycan of Fr. P, the relative content of chondroitin sulfate decreases with a concomitant increment in that of keratan sulfate on calcification. In addition, elevation of the ratio of chondroitin 4-sulfate to chondroitin 6-sulfate, together with a small increment of non-sulfated disaccharide units in the chondroitin sulfate chains appears to occur on calcification. The glycogen content in Fr. S diminished on calcification. The present observations suggest therefore that the remodeling of proteoglycan and consumption of glycogen in bovine costal cartilage occur on calcification.抄録全体を表示PDF形式でダウンロード (1732K) -
Masateru SHIN, Zen-ichi YOKOYAMA, Ayako ABE, Hirosuke FUKASAWA1979 年 85 巻 4 号 p. 1075-1081
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーWheat ferredoxin was purified from the leaves of common wheat (Triticum aestivums). The absorption spectrum showed maxima at 465, 425, 332, and 278nm. The absorbance ratio, A425nm/A278 nm was 0.49, and the millimolar extinction coefficient at 425nm was 10.8mM-1 cm-1 The amino acid composition was determined to be Lys5, His2, Arg1, Asp11, Thr5, Ser7, Glu18, Pro5, Gly6, Ala7, Cys5, Val7, Met1, Ile4, Leu7, Tyr4, Phe1, and Trp1. The total number of amino acid residues was 97. The molecular weight was calculated from the amino acid composition to be 10, 829, including iron and sulfur atoms. This value was confirmed by other methods, which were based on the contents of non-heme iron and of terminal amino acid. The N-terminal amino acid was alanine, and the C-terminal amino acid sequence was -Glu-Leu-Thr-AlaCOOH.
Comparative studies were performed between T. aestivum ferredoxin and ferredoxins isolated from closely related species; these were T. aegilopoides, T. durum, Ae. squarrosa, and Ae. ovata. No significant differences in the properties of these ferredoxins were detected. It was also shown that these ferredoxins are immunologically homologous. It is, therefore, likely that one molecular species of ferredoxin is distributed through two genera of Triticum and Aegilops.抄録全体を表示PDF形式でダウンロード (1128K) -
Hachiro OZAKI, Isamu SHIIO1979 年 85 巻 4 号 p. 1083-1089
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーA 5'-nucleotidase which absolutely required magnesium ions was found in the cytoplasm of Bacillus subtilis K No. 321, an inosine-producing bacterium. Another cytoplasmic 5'-nucle-otidase of the bacterium which is activated only slightly by magnesium ions has been reported previously. The enzymes were completely separated from each other by Sephadex G-200 gel-filtration of the sonic extract of the cells. The magnesium-requiring enzyme had a molec-ular weight of 23, 000, an optimum pH of 7.5, and showed specific activation by Mg2+. The enzyme hydrolyzed the phosphomonoester bonds of both purine and pyrimidine nucleoside-5'-monophosphates, but did not hydrolyze UDP-glucose, 4-nitrophenylphosphate or bis(4-nitrophenyl)phosphate. The Km value for AMP was 0.25 mm. Mn2+ and Co2+ activated the enzyme only slightly in the absence of Mg2+ but were rather inhibitory in the presence of Mg2+ The enzyme was strongly inhibited by Zn2+, Cult, and Fe2+. The inorganic phos-phate inhibition was of mixed type with respect to AMP, and the inhibitor constant for phos-phate was 1.5mM.
From strain No. 231 a mutant was derived which contained only the cytoplasmic magne-sium-requiring 5'-nucleotidase, and was deficient in other 5'-nucleotidases (the cell wall and membrane enzymes, the magnesium-non-requiring cytoplasmic enzyme, and the enzyme of culture supernatant). The mutant accumulated inosine in the culture medium to the same extent as the parent strain No. 231, indicating that the magnesium-requiring cytoplasmic en-zyme is involved in the extracellular accumulation of inosine in B. subtilis K.抄録全体を表示PDF形式でダウンロード (490K) -
Isarmu MATSUMOTO, Yuko MIZUNO, Nobuko SENO1979 年 85 巻 4 号 p. 1091-1098
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーThe optimal conditions for the activation of Sepharose by epichlorohydrin and subsequent immobilization of ligands were investigated. Under the optimal conditions for activation, namely, 30% Sepharose-5% epichlorohydrin-0.4M NaOH, 40°C, 2h, the maximum amount of epoxy group was introduced into Sepharose with low cross-linking. The adsorbents ob-tained by using N-acetyl-D-glucosamine, tri-N-acetylchitotriose, and glycoprotein as a ligand exhibited no nonspecific adsorption and good permeability for the high molecular substance to be purified, and were stable in an alkaline solution. Solanum tuberosum agglutinin was specifically adsorbed on a tri-N-acetylchitotriose-Sepharose column and was quantitatively recovered by elution with 0.2M ammonia solution. Furthermore, the column could be re-peatedly used under these conditions without reduction of its capacity.抄録全体を表示PDF形式でダウンロード (613K) -
Yoshikazu KURODA, Eikichi HASHIMOTO, Yonson KU, Yasutomi NISHIZUKA1979 年 85 巻 4 号 p. 1099-1101
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーCyclic AMP-dependent and cyclic GMP-dependent protein kinases (protein kinases A and G, respectively) utilize the same phosphate acceptor proteins when assayed in in vitro systems. Nevertheless, protein kinase A phosphorylates preferentially free histone, whereas protein kinase G greatly favors the histone which is associated with polydeoxyribonucleotide. On the other hand, when cytoplasmic soluble substrates such as phosphorylase kinase are used, the reactions are always more favorable for protein kinase A rather than for protein kinase G. Available evidence implies that the topographic relationship between enzyme and substrate may be an important determining factor for the functional specificities of these two classes of protein kinases.抄録全体を表示PDF形式でダウンロード (225K) -
Kazuyo OHASHI, Koscak MARUYAMA1979 年 85 巻 4 号 p. 1103-1105
発行日: 1979/04/01
公開日: 2008/11/18
ジャーナル フリーA new structural protein was purified from a prolonged 0.6M KI extract of residues of chicken skeletal myofibrils, from which myosin, actin, and some other proteins had been removed. The protein had a chain weight of 55, 000. The indirect immunofluorescence technique using antiserum against the 55, 000 dalton protein revealed that the protein was exclusively located in the Z lines of a myofibril. The new protein formed lattice structures in vitro which were similar to those observed in the Z lines in situ.抄録全体を表示PDF形式でダウンロード (721K)
- |<
- <
- 1
- >
- >|