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Volume 69 (1971)
- Issue 6 Pages 991-
- Issue 5 Pages 823-
- Issue 4 Pages 633-
- Issue 3 Pages 447-
- Issue 2 Pages 255-
- Issue 1 Pages 1-
Volume 69, Issue 4
Displaying 1-21 of 21 articles from this issue
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II. Effect of 6-Mercaptopurine on Formation of α-Acetolactate SynthaseYoshihiro ASADA, Kazuo YAMAGUCHI, Teijiro UEMURA1971 Volume 69 Issue 4 Pages 633-639
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA large amount of valine was accumulated in Aerobacter aerogenes No. 19-35 when 6-mercaptopurine (6-MP) or inorganic phosphate (P) was added to a Pi-poor medium, in which glutamic acid was usually accumulated. In order to clarify the mechanism of this conversion of amino acid accumulation, the role of α-acetolactate synthase (α-ALSase) for the conversion was investigated. It was revealed that activity of α-ALSase in valine-producing cells (Val-cells) was exceedingly higher than that in glutamic acid-producing cells (Glu-cells).
Optimum pH of α-ALSase in Val-cells was 6.0, while that in Glu-cells was 8.0. The pH 8.0-α-ALSase was sensitive to endproduct inhibition, while pH 6.0-α-ALSase was not. Furthermore, insensitive α-ALSase was induced by an addition of 6-MP or P. the induction being inhibited by chloramphenicol.
It was concluded that one of the mechanisms for the conversion of the amino acid fermentation is ascribed to the inducible formation of valine-insensitive pH 6.0-α-ALSase in the presence of 6-NIP or Pi.View full abstractDownload PDF (513K) -
Takaharu MIZUTANI1971 Volume 69 Issue 4 Pages 641-650
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe modification of tRNA1Val from Torulopsis utilis with [14C] N-cyclohexyl-N'-β-(4-methylmorpholinium) ethylcarbodiimide iodide (CMC) was studied. The modified tRNA1Val was fractionated according to the number of moles of CMC bound to the tRNA. The modified tRNA having one mole of CMC was completely active for valine acceptance. The activity of the tRNA having approximately two moles of CMC decreased to 24% of that of intact tRNA1Val but was recovered up to 80% after the removal of CMC by incubation at pH 10.3. Uridylic acid was the major modified residue in both of these cme-tRNA's. In the functionally active cmc-tRNA, which contains one mole of CMC, 0.3-0.4 mole of CMC was found as cmcUp whose position is followed by the anticodon sequence.View full abstractDownload PDF (616K) -
Tsuneo OMURA, Yoshiaki KURIYAMA1971 Volume 69 Issue 4 Pages 651-658
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSWhen a single intravenous injection of radioactive leucine was given to the rat, the labeled molecules of two microsomal enzymes in the liver, NADPH-cytochrome c reductase and cytochrome b5, appeared first in the rough microsomal membrane and subsequently in the smooth. This result is compatible with the idea that these enzymes are synthesized by the membrane-bound ribosomes in the rough region of the endoplasmic reticulum, and the newly formed enzyme molecules are then in-corporated into the membrane nearest to the site of their synthesis. The distri-bution of the labeled enzyme molecules between rough and smooth microsomal membranes became equal at about 2 hr after the labeling and remained the same afterwards. This suggests the reversible transfer in vivo of the new enzyme mole-cules between these two morphologically-different portions of the endoplasmic re-ticulum.
Examination of the total microsomal protein revealed, however, no significant difference in the distribution of new molecules between rough and smooth micro-somes. In the process of the incorporation of newly synthesized molecules into the membrane, the majority of the microsomal membrane proteins thus behaves differ-ently from the two specific enzymes examined in the present study.View full abstractDownload PDF (594K) -
Yoshiaki KURIYAMA, Tsuneo OMURA1971 Volume 69 Issue 4 Pages 659-669
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn spite of several lines of strong evidence for the molecular identity of the pheno-barbital-induced and normal NADPH-cytochrome c reductases in rat liver micro-somes, their stability in vivo was affected differently by phenobarbital-treatment. The reductase molecules synthesized under normal condition were stabilized by the administration of the drug, whereas their counterparts synthesized at the time when their rate of synthesis was maximally induced by the drug were degraded even during the treatment with the drug.
In the case of cytochrome b5, another microsomal enzyme whose rate of synthe-sis was not affected by phenobarbital, however, the enzyme molecules synthesized under the influence of the drug as well as those synthesized under normal condition were affected similarly by the drug in that their degradation was slowed down during the treatment. The administration of phenobarbital markedly affected the transfer from rough to smooth microsomes of newly synthesized NADPH-cytochrome c re-ductase molecules but not that of cytochrome b5.
These findings seem to indicate that the stimulated synthesis of NADPH-cytochrome c reductase by phenobarbital-treatment causes the alteration in the process of incorporation of the newly synthesized reductase molecules into microsomal mem-branes, resulting in the lowered stability of the “phenobarbital-induced” reductase.View full abstractDownload PDF (740K) -
The Template Activities of Nuclear RNAs from Rat Liver, Regenerating Liver and Hepatoma AH-130 CellsMinoru AMANO, Takiko AKINO1971 Volume 69 Issue 4 Pages 671-676
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe ability of simulating amino acid incorporation into protein by nuclear RNA from rat liver, regenerating rat liver and hepatoma cells was investigated by a protein synthesizing system with S-30 fractions from Eschcrichia coli. 1. The nuclear RNA from normal rat liver had the highest template activity; about 2.2 times more stimulation of 14C-leucine incorporation into protein than that from hepatoma cells.
2. The nuclear RNA of the liver regenerated for 16 hr after hepatectomy had about 80% of template activity of that of normal rat liver.
3. In all nuclear RNAs from these three cells, the highest template activity was found in the rapidly sedimenting 35S and 45S RNA regions, and no activity was found in low molecular RNA.
4. The distribution of RNA molecular species having the capacity for stimulating 14C-leucine incorporation in nuclear RNA extracted from normal rat liver displayed a pattern with maximum activity in the 18S region, but that from hepatoma had a broad pattern with the highest activity in the 35S region.
5. Nuclei of regenerating liver had polydisperse RNA having strong template activity in the 18S and 35S regions.View full abstractDownload PDF (384K) -
Hiromichi OKUDA, Frank. J. SEK, Setsuro FUJII1971 Volume 69 Issue 4 Pages 677-681
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAdrenaline-induced lipolysis was considerably inhibited by preincubation of adipose tissue at lower temperatures (0°C or-10°C). cAMP, theophylline and DBcAMP-induced lipolysis was also inhibited by preincubation of adipose tissue at lower tem patures. On the other hand, a hormone-sensitive lipase activity remained unchanged after the preincubation at lower temperatures.
A possible mechanism of cooling effect on adrenaline-induced lipolysis was dis-cussed.View full abstractDownload PDF (288K) -
Shunji HOSOKAWA, Masachika IRIE1971 Volume 69 Issue 4 Pages 683-697
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1) Two ribonuclease [EC 2. 7. 7. 16], RNases Vs1 and Vs2, were isolated from bovine seminal vesicles. They were purified 380 and 460 fold respectively, by CM-cellulose, Sephadex G-75 and P-cellulose column chromatographies. Both enzymes were homo-geneous on gel electrophoresis.
2) The molecular weights of RNases Vs1 and Vs2 were 25, 500 and 13, 000, respec-tively as determined by means of gel filtration. The latter enzyme was different from bovine pancreatic RNase A on gel electrophoresis.
3) RNases Vs1 and Vs2 were very similar to RNase A in respect of base specificity, pH optimum, stability and behavior against heavy metal ions, such as Zn2+ and Cu.2+ 4) Amino acid composition of RNase Vs1 was reported. The amino-and carboxyl-terminal amino acids of the enzyme were lysine and valine, respectively and coin-cided with those of bovine pancreatic RNase A.View full abstractDownload PDF (1802K) -
Takashi TAKAGI, Sadaaki IWANAGA1971 Volume 69 Issue 4 Pages 699-709
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA cross-linked polypeptide chain involved in stabilized bovine fibrin was isolated by two cycles of gel-filtration on a Sepharose 6 B column and chromatography on a CM-cellulose column after sulfitolysis of the parent protein. The isolated chain designated as “X2” was homogeneous electrophoretically. The molecular weight of “X2” -vas estimated to be approximately 110, 000 by the method of Andrews. This value is significantly different from the average molecular weight of 58, 000 of the α, β and γ-chain peptides in fibrin. However, the amino acid compositions, N-terminal residues and peptide mappings of “X2” and the γ-chain peptide were quite similar. The N-terminal residue of both was tyrosine, and their tryptic peptide maps differed only in the distributions of a few spots. Furthermore, no tryptic peptides derived from the α-and β-chain peptides were detected in the peptide map of “X2” suggesting that the α-and β-chains were not involved in the cross-links. The following con-clusion are drawn from these results: (1) The cross-linked chain, “X2” isolated from S-sulfo-stabilized fibrin is composed of the γ-chain peptide, one of the three subunits of the fibrin molecule. “X2” seems to contain two γ-chain peptides. 2) The chain peptides which are linked together must contain both donor and acceptor sites respectively, to construct the cross-linkage, ε-(γ-glutamyl)-lysine. (3) Thus, it seems that the cross-linkage, which stabilizes the fibrin clot formed by the action of activated FSF, mainly involves a pair of γ-chain peptides in the fibrin molecule.View full abstractDownload PDF (2576K) -
Hiroshi KIMURA, Hachiro NAKAGAWA1971 Volume 69 Issue 4 Pages 711-723
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSCystathionine synthetase was purified approximately 1, 000 fold from rat liver by the following procedures: treatment at pH 5.5, 1st ammonium sulfate fractionation, 1st DEAE-cellulose column chromatography, 2nd ammonium sulfate fractionation, 2nd DEAE-cellulose column chromatography, treatment with P-cellulose, and column chromatographies on Bio-Gel P-300 and hydroxylapatite.
The purified enzyme still separated into 5 bands on disc-electrophoresis but was shown to be more than 90% pure, as judged by this procedure.
It was demonstrated by molecular sieve chromatography that the molecular weight of the crude and partially purified preparations of cystathionine synthetase was 250, 000, while that of highly purified enzyme was 112, 000. This suggests that cystathionine synthetase of rat liver consists of 2 functional subunits with synthe-tase activity and dissociates into subunits during purification. Neither the dissociated form (highly purified enzyme) nor the associated form (partially purified enzyme), however, exhibited serine dehydratase activity.
Pyridoxal phosphate was shown to be a cofactor of the enzyme. The dissociation constant of the cofactor was calculated to be 5×10-5M.
The Km values for L-serine and L-homocysteine were calculated to be 6.7×10-4M and 1.1×10-3M, respectively.
Inorganic sulfur and various amino acids including L-cystine, L-cysteine and L-methionine had no effect on the enzyme activity in vitro.View full abstractDownload PDF (844K) -
Keiko KATO, Takashi MURACHI1971 Volume 69 Issue 4 Pages 725-737
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSHen egg-white lysozyme [EC 91. 2. 1. 17] has three tyrosyl residues per molecule at positions 20, 23, and 53. The tryptic peptides which contain each one of these tyrosyl residues were located on the chromatographic fractions obtained from reduced and S-carboxymethylated lysozyme. The fractionation experiments were also carried out with lysozyme samples which had been prepared by modification with diisopro-pylphosphorofluoridate tDFP) under various conditions. The yields of the peptides which contained modified tyrosyl residues were compared with the yields of the corresponding tyrosine-containing peptides from unmodified lysozyme. The degree of modification of each tyrosyl residue was thus calculated.
The data obtained show that tyrosyl residues at positions 20 and 23 are both partially modified by DFP, and that the degrees of modification increase as the pH of the reaction medium is increased from 9. 5 to 10. 2 or 10. 7. The reactivities of tyrosyl residues at positions 20 and 23 are not much different: they react with DFP alternatively but not simultaneously. Tyrosyl residue at position 53 was found to remain unmodified unless the reaction with DFP was carried out in the presence of 3M or 5M guanidine hydrochloride. In 5 M guanidine hydrochloride at pH 10. 2, a quite extensive modification occurred at all of the three tyrosyl residues. These results are consistent with the known three-dimensional structure of lysozyme as well as the data on spectral characteristics of DFP-modified lysozyme preparations reported earlier from this laboratory.View full abstractDownload PDF (961K) -
Q. Perveen GHANI, Shizuo WATANABE1971 Volume 69 Issue 4 Pages 739-752
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn the presence of a calcium chelator, namely ethylene glycol-bis-(β-aminoethylether)-N-N'-tetraacetic acid, glycerinated muscle fibers can undergo both contraction and relaxation as effectively in inosine triphosphate (ITP) media as in adenosine triphos-phate (ATP) media. Like the ATP-induced superprecipitation, the ITP-induced superprecipitation requires only magnesium in the absence of relaxing protein, and requires both magnesium and calcium in the presence of relaxing protein. As in ATP media, a phenomenon called the burst hydrolysis is also observed in ITP media. Even the effects of p-chloromercuribenzoate (CMB) and of adenosine di-phosphate (ADP) are essentially the same in ITP media as in ATP media. How-ever, there still remain significant differences between ITP-and ATP-induced super-precipitations. Some of these differences can be explained by assuming that the presence in the nucleotide purine ring of an OH group (ITP) or NH2 group (ATP) makes a great difference in the nucleotide binding with myosin A as well as in a subsequent process of a conformational change in myosin A. On the other hand, some other differences suggest that the molecular events involved in the ITP-induced superprecipitation are different from those involved in the ATP-induced superprecipi-tation. Such differences are: (a) Calcium without CMB or ADP removes the in-hibition of superprecipitation completely in ITP media but only partially in the ATP media. (b) The magnesium requirement is different from the nucleotide require-ment in ITP media whereas they are the same in ATP media. (c) The pH de-pendence of the ITP effect has been well-known to be different from that of the ATP effect.View full abstractDownload PDF (962K) -
Nobuhito SONE1971 Volume 69 Issue 4 Pages 753-760
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe occurrence and nature of a pigment found in the cells of Propionibacterium arabinosum were studied. In the oxidized form the pigment has absorption maxima at 416 (Soret), 529 (β) and 561 (α) mμ, and in the reduced form at 392 (Soret) and 554 (α) mμ. The pigment is produced when cobalt is present in the growth medium and the presence of iron inhibits its production. After purification, by procedures including denaturation of proteins, the pigment was identified as cobalt copropor-phyrin III with absorption peaks in the oxidized form at 410, 525 and 558mμ, and in the reduced form at 390 and 552mμ. The difference of the absorption maxima of the pigment before and after purification may be due to the binding of the pig-ment with proteins in the cells. This binding of the pigment with proteins, how-ever, does not seem to be specific. Based on the above results the significance of the formation of the pigment is discussed in relation to the biosyntheses of porphyrins and vitamin B12.View full abstractDownload PDF (531K) -
III. A Classification of Transfer Ribonucleic Acids by the Elution Profiles on Gel Filtration and Sedimentation Profiles on Sucrose Density GradientNobuyoshi SHIMIZU1971 Volume 69 Issue 4 Pages 761-770
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSElution profiles on gel filtration (Sephadex G-100) and sedimentation profiles on sucrose density gradient were compared for transfer RNAs (tRNAs) from two “living fossils” and from eleven species of “present organisms.”
These various species of tRNAs showed a similar coefficient of distribution, Kd value, in the denatured state, which reflects a similar molecular length on an aver-age.
However, they were classified into two groups from their Kd values in the native state. Group I (Kd=0.17) includes five bacterial tRNAs (E. coli, S. typlzimurium, B. subtilis, B. cereus and P. vulgaris) and yeast tRNA. Group II (Kd≥0.19) includes five species of tRNAs from fungus (A. oryzae), plant (spinach), insect (silk-worm) and mammalian (rat liver and rabbit liver). tRNAs from living fossils (brachiopod Lingula and horseshoe crab Limulus) are also included in the group II, although their Kd values are somewhat larger. Sedimentation profiles on sucrose density gradient supported this classification.View full abstractDownload PDF (643K) -
Kunio YAMANE, Takafumi YOSHIKAWA, Hiroshi SUZUKI, Kazutosi NISIZAWA1971 Volume 69 Issue 4 Pages 771-780
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSOf the cellulase [EC 3. 2. 1. 4] components A, B and C produced by Pseudomonas fluorescens var. cellulosa, the last one was usually localized in ‘intrawall’ or peri-plasmic fraction of the cell which was solubilized by spheroplasting with a combined action of lysozyme [EC 3. 2. 1.17] and EDTA. In contrast, cellulases A and B oc-curred mainly in extracellular fraction or culture medium. In the cytoplasmic fraction, only a very small amount of cellulase was found to be present, and its properties could not be examined in this work. On the basis of the localities of these cellulase components in the cell and their particular substrate specificities, their physiological significance was discussed.View full abstractDownload PDF (589K) -
Purification and Some Properties of the EnzymeMotoo TSUSUÉ1971 Volume 69 Issue 4 Pages 781-788
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSepiapterin deaminase catalyzes the hydrolysis of sepiapterin to xanthopterin-B2 and ammonia. The enzyme was highly purified from the extract of the larval integument of the silkworm mutant, “lemon.” The enzyme has an optimum pH at 8.0 and the Km value for sepiapterin was found to be 5.9×10-4M. The enzyme is specific for sepiapterin, and isosepiapterin is less effectively deaminated. Other pteridines tested, such as 2-amino-4-hydroxypteridine, xanthopterin and biopterin inhibit the deaminase activity. The stoichiometry of the deaminase reaction was established from balance studies. The enzyme is widely distributed in the larval tissues of this silkworm mutant, however, the biological role of the enzyme remains unknown.View full abstractDownload PDF (491K) -
Tsutomu NOJIRI, Fumihiko TANAKA, Iwao NAKAYAMA1971 Volume 69 Issue 4 Pages 789-801
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. An enzyme, phosphotransacetylase [acetyl-CoA: orthophosphate acetyltransferase, EC 2. 3. 1. 8], which catalyzes the reversible transfer of an acetyl group from acetyl-Coenzyme A to phosphate, was isolated from extracts of Lactobacillus fermenti strain 36, IFO No. 3071 (ATCC No. 9338).
2. The purest preparation of phosphotransacetylase with a specific activity of 1, 124 μmoles per min per mg protein appeared almost homogeneous on polyacrylamide-disc electrophoresis.
3. The enzyme has a molecular weight of 68, 000 estimated by gel filtration. The elution pattern of the enzyme on Sephadex G-150 gel filtration was quite similar to that of Clostridium phosphotransacetylase.
4. The enzyme has its maximum activity at pH 7.6 in Tris-HCl buffer.
5. The Km value for Coenzyme A was estimated as 8.7×10-5M.
6. The enzyme has an isoelectric point at pH 4.1 estimated by the ampholine electro-focussing method.
7. NH4+, K+, and Rb+ are required for maximum activity, but Ca2+ Mg2+ Ba2+ Li+, Cs+, and SO42- are inhibitory. EDTA, NAD+, and NADH have not appreciable effects.
8. The equilibrium constant for acetylation of Coenzyme A was estimated to be 134±20 at 27°C, pH 7.6.View full abstractDownload PDF (770K) -
Akiyuki OHKUBO1971 Volume 69 Issue 4 Pages 803-805
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (175K) -
IV. Hydroxamate Formation from a Phosphorylated Intermediate and 2-Hydroxy-5-nitrobenzyl HydroxylamineTaibo YAMAMOTO, Atsunobu YODA, Yuji TONOMURA1971 Volume 69 Issue 4 Pages 807-809
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (146K) -
M. RICHARDSON, D. RICHARDSON, J. A. M. RAMSHAW, E. W. THOMPSON, D. BOU ...1971 Volume 69 Issue 4 Pages 811-813
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (187K) -
Hiroshi MORIYA, Noriko TODOKI, Chiaki MORIWAKI, Yoshio HOJIMA1971 Volume 69 Issue 4 Pages 815-817
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (154K) -
Masaru SOGAMI1971 Volume 69 Issue 4 Pages 819-822
Published: April 25, 1971
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (235K)
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