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Volume 74 (1973)
- Issue 6 Pages 1075-
- Issue 5 Pages 863-
- Issue 4 Pages 639-
- Issue 3 Pages 405-
- Issue 2 Pages 203-
- Issue 1 Pages 1-
Volume 74, Issue 4
Displaying 1-27 of 27 articles from this issue
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Toshisuke KAWASAKI, Ikuo YAMASHINA1973 Volume 74 Issue 4 Pages 639-647
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSGlycopeptides were prepared by pronase digestion from membranous proteins of rough and smooth microsomes, and were then fractionated by chromatography on Sepha-dex G-50 and on DEAE-Sephadex A-25 yielding a number of glycopeptides which could be classified as neutral or acidic glycopeptides.
The size and composition of acidic glycopeptides from the rough and smooth membranes differed, while those of the neutral glycopeptides were similar. Neutral glycopeptides were predominant in rough membrane, comprising about 60% of the total on a molar basis, whereas acidic glycopeptides were predominant in smooth membrane, comprising about 90%. This difference is too great to be accounted for by contamination of the smooth membrane by the plasma membrane, which con-tains only acidic oligosaccharide chains. Rather, it was suggested that the endo-plasmic reticula constituting rough and smooth microsomes differ from each other as regards the pattern of oligosaccharides attached to the membranous polypeptides.View full abstractDownload PDF (1766K) -
Toshiaki HIRATSUKA, Ichiro SAKATA, Koki UCHIDA1973 Volume 74 Issue 4 Pages 649-659
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn analog of ATP, N6-(2, 4-dinitrophenyl)-adenosine 5'-triphosphate (DNP-ATP), in which a dinitrophenyl group replaces a hydrogen of the 6-amino group of the ade-nine base, has been synthesized by the reaction of FDNB with ATP under mild conditions. The DNP-ATP prepared was homogeneous on paper chromatography and could replace ATP for heavy meromyosin ATPase [EC 3. 6. 1. 3]. Heavy mero-myosin catalyzed the release of the terminal phosphate from DNP-ATP at Vmax, 0.33μmole per min per mg, which was 57% of that observed for ATP.
The difference spectrum of heavy meromyosin induced by DNP-ATP was measured in the presence of MgCl2. The spectrum showed two peaks at 281mμand at 288mμ, a shoulder at 292mμ, and broad negative troughs in the 240 to 270mμ region and in the 300 to 360mμ region. The hypochromicity at the higher wavelength is due to the interaction of the dinitrophenyl group with heavy mero-myosin. The difference absorbance at 320mμ observed after the addition of DNP-ATP was a function of the concentration of DNP-ATP added. However, the plot deviated from a hyperbolic curve, having a sigmoidal character.View full abstractDownload PDF (833K) -
Fujio SUZUKI, Hideo INOUE, Yoshiro TAKEDA1973 Volume 74 Issue 4 Pages 661-666
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe relation between growth hormone and thioamide derivatives in induction of ornithine decarboxylase [EC 4. 1. 1. 17] was studied in comparison with the induction of enzyme by pentobarbital, a secretagogue of growth hormone in the rat. After a single injection of hexanoylthiourea, hepatic ornithine decarboxylase activity markedly increased, with a peak after 15 hr, whereas the plasma growth hormone level decreased progressively with time for a period of 24 hr. The lowered level of growth hormone increased to normal after 35 hr. Thioacetamide, which also elevates the enzyme activity in the liver, caused no significant change in the plasma level of growth hormone. Pentobarbital raised the plasma level of growth hormone very rapidly and induced ornithine decarboxylase in the liver. The maximal activity of ornithine decarboxylase was observed 4hr after its injection and then the activity decreased sharply and returned to the control value after 6hr.
The mode of action of hexanoylthiourea in induction of ornithine decarboxylase was discussed, especially in relation to growth hormone.View full abstractDownload PDF (483K) -
Osamu DOI, Shoshichi NOJIMA1973 Volume 74 Issue 4 Pages 667-674
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDetergent-resistant(DR) phospholipase A [EC 3. 1. 1. 4] in E. coli K-12 showed both A1 and A2 activities. It also hydrolyzes both 1-acyl and 2-acyl GPE. These activities were not detected or were detected to a lower extent in DR phospholipase A-less mutants. Both DR phospholipase A1 and A2 showed similarities in optimum pH, localization in membrane fraction, and susceptibility to trypsin treatment, and it was difficult to find evidence that A1 and A are different enzymes.View full abstractDownload PDF (602K) -
Toshifumi KIYOHARA, Mitsugu FUJII, Teruo IWASAKI1973 Volume 74 Issue 4 Pages 675-682
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA specific peptide bond of potato proteinase inhibitor I is hydrolyzed by incubation with a catalytic amount of chymotrypsin [EC 3. 4. 4. 5] at pH 3. The inhibitor thus modified is separated into two fragments by reduction, S-carboxymethylation and subsequent gel filtration on a Sephadex G-50 column. The terminal amino acids and amino acid compositions of these two fragments show that incubation of the inhibitor with chymotrypsin causes the cleavage of a single peptide bond, Leu56-Asx57, within a disulfide loop of the inhibitor molecule. An inhibitor-enzyme complex is formed by incubation of the chymotrypsin-modified inhibitor with equi-molar Nagarse at pH 7.6. Amino-and carboxyl-terminal amino acids and the amino acid composition of inhibitor which was dissociated from this inhibitor-enzyme complex at acid pH, are consistent with those of native inhibitor. This fact shows that the cleaved peptide bond, Leu56-Asx57, of the chymotrypsin-modified inhibitor is resynthesized by Nagarse at near neutral pH.
It may therefore be concluded that the chymotrypsin-susceptible peptide bond, Leu56-Asx57, is the main reactive site of the inhibitor for both chymotrypsin and Nagarse. Further, other experimental results indicate that this reactive site is also utilized for the inhibition of the alkaline proteinases of Aspergillus sydowi, Asper-gillus sulphureus, and PenicUlium chrysogenum.View full abstractDownload PDF (583K) -
Akio NAKAMURA, Shigeki MINAKAMI1973 Volume 74 Issue 4 Pages 683-689
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1) The turnover of inactivated catalase [EC 1. 11. 1. 6] was studied by injection of radioactive 3-amino-l, 2, 4-triazole(AT). The livers of rats injected with14C-AT were fractionated into peroxisomal and soluble fractions and the disappearance of the radioactivity from protein precipitated with anti-catalase antibody was determined. The half-life of the radioactivity in catalase protein was about 2 days for peroxisomes and less than a day for cytosol.
2) The immunoprecipitation curves of catalase and AT-catalase obtained with anticatalase antiserum demonstrated that catalase and AT-catalase were identical in their antigenic properties and formed the same amount of immunoprecipitate with anti-catalase antiserum.
3) Changes in the amounts of immunoprecipitates in peroxisomes and cytosol were determined after treatment with AT. The amount of immunoprecipitates in the peroxisomes remained unchanged after inhibition by AT, which indicates that the peroxisomal catalase behaves in the degradation process in a way which is essentially unaltered by inactivation. On the other hand, the immunoprecipitate in cytosol decreased on AT treatment, suggesting that the degradation rate of cytosol catalase is accelerated by the modification.View full abstractDownload PDF (563K) -
Michinao MIZUGAKI, Mitsuru UCHIYAMA1973 Volume 74 Issue 4 Pages 691-696
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn enoyl CoA reductase, solubilized from rat liver mitochondria by sonication, catalyzes the reduction of both oct-cis-2-enoyl CoA and its trans isomer in the presence of NADPH as a specific electron donor. The reduction of these two enoates by the reductase resulted in the transfer of hydrogen from the A-side of NADPH. The possible role of the reductase in the β-oxidation pathway of unsaturated fatty acids is discussed.
The identification of oct-cis-2-enoate and the trans isomer by GC-MS and TLC are also described.View full abstractDownload PDF (426K) -
VIII. Disulfide Bridges in Soybean Bowman-Birk Proteinase InhibitorShoji ODANI, Tokuji IKENAKA1973 Volume 74 Issue 4 Pages 697-715
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSoybean Bowman-Birk proteinase inhibitor contains 14 half-cystine residues in a relatively short polypeptide chain of 71 amino acid residues, and five half-cystine residues around the trypsin-inhibitory site are in absolutely identical locations to those around the chymotrypsin inhibitory site. To assign the locations of the disulfide bridges, the native inhibitor was digested with a mold acid proteinase, thermolysin, pronase or subtilisin to yield cystine peptides suitable for structural investigation. These were separated and purified by chromatography on a Bio-Gel P-4 column and by paper electrophoresis. A peptide containing a-Cys-Cys-sequence was further hydrolysed with 10N sulfuric acid. Amino acid analyses and appropriate amino terminal analyses of the resulting cystine peptides or their oxidized derivatives revealed the positions of 7 disulfide bridges in the parent molecule, which indicated the presence of two homologous trypsin-and chymotrypsin-inhibitory regions, and an almost symmetrical structure of the inhibitor.View full abstractDownload PDF (1326K) -
I. Microsomal S-TransmethylaseTakeshi FUJITA, Ziro SUZUOKI1973 Volume 74 Issue 4 Pages 717-722
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSEnzyme systems responsible for the novel metabolic pathway of foreign mercaptans leading to the formation of methylsulfonyl metabolites were investigated in rat tissues. The first step was shown to be S-transmethylation. Tetrahydrofurfuryl mercaptan was methylated to its methyl sulfide by liver homogenates in the presence of S-adenosylmethionine. The activity was highest in liver, followed by kidney and small intestine. The hepatic activity was located exclusively in microsomes. The apparent Michaelis constants were 2.5×1O-4M for the acceptor substrate and 1.0×1O-4M for S-adenosylmethionine. The activity was completely inhibited by p-chloromercuribenzoate, p-chloromercuribenzenesulfonate or HgCl2, whereas it was enhanced by GSH, cysteine or ascorbate.View full abstractDownload PDF (454K) -
II. Sulfide and Sulfoxide Oxygenases in MicrosomesTakeshi FUJITA, Ziro SUZUOKI, Seizi KOZUKA, Shigeru OAE1973 Volume 74 Issue 4 Pages 723-732
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe second step in the enzymatic process responsible for the novel metabolic pathway of foreign mercaptans leading to methylsulfonyl metabolites was shown to be sulfoxidation, subsequent to S-methylation. By using [35S]methyl tetrahydrofurfuryl sulfide (MTFS) and [35S]methyl tetrahydrofurfuryl sulfoxide (MTFSO) as substrates, the occurrence and involvement of both sulfide and sulfoxide oxygenases were demon-strated in rat liver microsomes. Both activities required NADPH and O2. The reaction products were isolated and identified as MTFSO and its sulfone, respectively. The apparent Michaelis constants were 6.7×1O-4M for MTFS and 9.1×1O-5M for NADPH with sulfide oxygenase and 5.6×10-3M for MTFSO and 5.0×10-5M for NADPH with sulfoxide oxygenase, respectively. p-Chloromercuribenzoate, p-chloro-mercuribenzenesulfonate, HgCl2, and menadione strongly inhibited both oxygenases. Polyanions, such as inorganic phosphate, pyrophosphate, sulfate, and ATP stimulated both enzyme activities, especially that of sulfoxide oxygenase. One atom of18O2 was incorporated into the products in both enzyme reactions. No appreciable incor-poration was observed from H218O. These results indicate that both enzyme systems are typical mono-oxygenases.View full abstractDownload PDF (737K) -
III. Oxidative Cleavage of the Tetrahydrofuran MoietyTakeshi FUJITA, Ziro SUZUOKI1973 Volume 74 Issue 4 Pages 733-738
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIn vitro metabolism of the tetrahydrofuran ring was studied using [35S]methyl tetrahydrofurfuryl sulfone as a substrate with rat liver homogenates. The tetrahydrofuran ring was first hydroxylated by liver microsomes in the presence of NADPH and O2. The reaction product was isolated and identified as methyl 5-hydroxytetrahydrofurfuryl sulfone by instrumental analyses of the infrared, nuclear magnetic resonance, and mass spectra. An NADH-generating system could not support this microsomal hydroxylation, and the involvement of a peroxidative reaction was excluded. Methyl 5-hydroxytetrahydrofurfuryl sulfone thus formed was further oxidized to 4-hydroxy-5-methylsulfonylvaleric acid by incubation with the hepatic cytosol. Microsomes were no longer necessary for the second reaction. These results indicated that the tetrahydrofuran ring was first hydroxylated at the 5-position by microsomes and further cleaved to the straight-chain fatty acid via the intermediate formation of either an aldehyde form or a γ-lactone in the presence of cytosol.View full abstractDownload PDF (444K) -
IV. Induction of Microsomal S-Transmethylase, and Sulfide and Sulfoxide Oxygenases in the Drug-treated RatTakeshi FUJITA, Akio TERAOKA, Ziro SUZUOKI1973 Volume 74 Issue 4 Pages 739-745
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe influence of drug pretreatment was investigated on three novel microsomal enzyme activities: S-transmethylase, and sulfide and sulfoxide oxygenases, responsible for the biotransformation of foreign mercaptan sulfur in the rat. S-Transmethylase activity was induced by treatment with 3-methylcholanthrene, but not by phenobarbital. On the other hand, both oxygenase activities were enhanced about 2-fold by treatment with phenobarbital, but not by 3-methylcholanthrene administration.
These three enzyme activities were not appreciably influenced by treatment with tetrahydrofurfuryl mercaptan, methyl tetrahydrofurfuryl sulfide and its sulfoxide, which were the respective substrates. Thiamine tetrahydrofurfuryl disulfide, the parent compound of these metabolites, failed to induce these three enzyme activities when administered either intraperitoneally or orally to the rat. Pretreatment with thiamine tetrahydrofurfuryl disulfide and related metabolites caused no significant influence on either the microsomal activities of aniline hydroxylase [EC 1. 14. 1. 1], aminopyrine N-demethylase, and NADPH-cytochrome c reductase, or the microsomal content of cytochrome P-450.View full abstractDownload PDF (499K) -
Hanpei KIDO, Yurie SHIMAZU, Masako UEKI, Kikuo OGATA1973 Volume 74 Issue 4 Pages 747-756
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSEmploying livers from rats fed a protein-free diet for two weeks, the effects of protein deficiency on serum albumin-synthesizing activity were investigated and the following results were obtained.
1. While the incorporation of14C-leucine into the total protein of the postmitochondrial (S12-) fraction or the ribosomal fraction by liver slices from protein-deficient rats after overnight fasting did not decrease as compared with that of normal rat liver slices, the activity incorporated into the serum albumin fraction decreased significantly in the case of protein-deficient rats. Only a part of the decreased activity resulted from calorie deficiency due to the decrease in the food intake of the protein-deficient rats, since the incorporation of14C-leucine into the serum albumin fraction of liver slices from control calorie-deficient rats was significantly higher than that of the protein-deficient rat liver slices, although lower than that of normal rat liver slices. Furthermore, 2hr after refeeding the diet specific for each group, the albumin-synthesizing activity of protein-deficient rat liver slices was significantly lower than that of normal rat liver slices, although the activity increased in both groups of rats after refeeding.
2. The time course of the effect of refeeding complete diet to the protein-deficient rats on the incorporation of14C-leucine into various fractions by liver slices was examined. The incorporations into the S12-fraction and ribosomal fractions increased rapidly after refeeding, reaching maximal values at 12 and 2hr, respectively. Although incorporation into the serum albumin fraction also increased rapidly up to 12hr, it continued to increase gradually, reaching a maximal value at about 120hr.
3. Total liver polysomes from protein-deficient rats showed a lower activity in albumin synthesis than those from normal rats. The pattern of sucrose gradient centrifugation showed that polysomes heavier than the hexamer decreased in protein-deficient rat liver. Membrane-bound polysomes also decreased in the deficient liver.
4. Polysomes containing nascent albumin decreased significantly in protein-deficient rat liver as compared with normal rat liver.
5. Experiments with a rabbit-reticulocyte lysate system showed that the template activity for serum albumin synthesis of the total postmitochondrial RNA from protein-deficient rat liver was lower than that from normal rat liver.
6. These results may indicate that the low activity for albumin synthesis in protein-deficient rat liver may partly arises from a decrease of specific messenger RNA for serum albumin.View full abstractDownload PDF (851K) -
I. Purification and Characterization of the Enzyme from the Exocarp of Citrus natsudaidai HAYATAYukiho KUBOTA, Shozo SHOJI, Takayuki FUNAKOSHI, Hiroshi UEKI1973 Volume 74 Issue 4 Pages 757-770
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn enzyme, carboxypeptidase CN, was separated from the exocarp of Citrus natsudaidai HAYATA. The enzyme was homogeneous in disc electrophoresis and ultracentrifugal analysis. It liberated neutral, acidic, and basic amino acids including proline from the C-termini of N-substituted dipeptides at varying rates. Of the substrates tested, Z-Gly-Pro, Z-Pro-Pro, and Z-Glu-Pro were hydrolyzed very slowly. The enzyme hydrolyzed Z-Gly-Pro-Leu-Gly, the oxidized B chain of bovine insulin, and bradykinin potentiator C sequentially from their C-termini. The specific activity of the purified enzyme was 65.4 units per mg of protein for Z-Glu-Phe. It possessed weak esterase activity, but was free from endopeptidase and aminopeptidase activities. It had a pH optimum at pH 5.5 for Z-Glu-Phe. It was strongly inhibited by HgCl2 and DFP, but not by other metal ions, anions, EDTA, or o-phenanthroline. NEM, PCMB, DTT, and MIA showed no significant effect on the enzymatic activity at pH 5.5. Slow inactivation, however, occurred when the enzyme was preincubated with PCMB at pH 7.0. The values of s20, w and D20, w were 5.5S and 5.5×1O-7cm2 per sec, respectively, and the molecular weight was calculated to be 93, 000 from these values.View full abstractDownload PDF (2134K) -
Norio KATOH, Shuichiro KUBO, Hiroshi TAKAHASHI1973 Volume 74 Issue 4 Pages 771-778
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESS1. Immunological analyses of light chains prepared from highly purified myosin showed the presence of two kinds of light chain components. The light chains were separated, usually into two components, L-1 (molecular weight 27, 000) and L-2 (17, 000), by SDS-gel electrophoresis. However, an additional component, L-3 (14, 000) sometimes appeared in the electrophoresis pattern.
2. The light chains were fractionated into four components: L-1 (molecular weight 27, 000), L-2 (17, 000), L-3 (14, 000), and L-4 (8, 000-9, 000) by chromatography on SP-Sephadex C-50 in 5M urea. L-4 differed from the other components with respect to the ratio of Phe to Tyr content as determined by amino acid analysis and ultraviolet absorption spectra.
3. Immunological identity and chemical similarity were observed between L-1 and L3, and between L-2 and L-4. These results indicated that the light chains comprised L-1 and L-2, and that L-3 and L-4 were breakdown products of L-1 and L-2, respectively.
4. Treatment of chicken myosin with 5, 5'-dithiobis-(2-nitrobenzoic acid) resulted in specific dissociation of the L-2 component.View full abstractDownload PDF (3907K) -
IX. Conformational Change of Isozyme I in VitroKenji AKI, Tetsuro YOSHIMURA, Akira ICHIHARA1973 Volume 74 Issue 4 Pages 779-784
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThere are two forms of branched chain amino acid transaminase [EC 2. 6. 1. 6] in hog kidney supernatant. These forms (enzymes I and III) can be separated by either DEAE-cellulose column chromatography or polyacrylamide gel electrophoresis and the distribution ratio of enzymes I and III in the crude supernatant is 3 to 7. When the fraction of enzyme I obtained by DEAE-cellulose column chromatography was frozen for 3 weeks and then thawed, it was found on rechromatography to consist of enzyme I and a new active fraction (enzyme I') which was eluted in the position of enzyme III and the distribution ratio of the two forms was 1 to 9. The mobilities of enzyme I' and enzyme III were also the same on polyacrylamide gel electrophoresis. The enzyme I' derived from enzyme I could not be distinguished from enzyme III found in the crude supernatant by its Km values for substrates or cofactor or its molecular weight. But results of the complement fixation test and of studies on its susceptibility to proteolysis and the time course of its binding to cofactor showed that it was slightly different. The results on this conversion indicate that the enzyme I' is a conformational variant of enzyme I, and that it has a very similar structure to enzyme III.View full abstractDownload PDF (465K) -
Shigeru KUROOKA, Yoshio YOSHIMURA1973 Volume 74 Issue 4 Pages 785-795
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSIt was observed that human serum contained a substance which released mercaptoethanol from S-lauroylmercaptoethanol (S-LME). The activity was found to be associated with serum albumin by means of Sephadex G-200 gel filtration, electrophoresis on a cellulose acetate block, isoelectric focusing in carrier ampholites, and DEAE-Sephadex A-50 chromatography.
The mercaptoethanol releasing (MER) activity per mg of both crystalline human serum albumin (HSA) and albumin in serum was the same, and was high at pH 9-10 and negligible at pH below 7. The MER activity was also found in serum albumins from other mammals, but not in ovalbumin. Among S-C10, S-C12, S-C14, and S-C16 acyl-mercaptoethanols tested at pH 8.0, S-LME (C12) was the best substrate whereas O-acetyl-S-LME was not attacked, suggesting that the OH group of S-LME is necessary for the interaction. The MER activity was reduced about 50% by various anionic or non-ionic lauryl derivatives at concentrations of 0.02-0.05mM or 8M urea, and completely lost when HSA was acetylated by N-acetylimidazole or acetic anhydride, maleylated with maleic anhydride, digested with pepsin [EC 3. 4. 4. 1], or treated at 70°C for 3min. The MER activity was diminished greatly after about 8moles of mercaptoethanol had been released per one mole of HSA.
From these results, the MER interaction between S-LME and HSA seems to be the acylation reaction specific for some of the ε-NH2 groups of lysine or hydroxyl group of S-LME, of which the former residues are more probable reactants since the S-LME treated HSA shows no decrease in absorbance at around 278nm.
The MER reaction is specific for serum albumin and the MER activity assay method can be applied for the determination of serum or urinary albumins.View full abstractDownload PDF (835K) -
Hisako HOSONO, Sigeru KUNO1973 Volume 74 Issue 4 Pages 797-803
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSCytidine deaminase [cytidine aminohydrolase, EC 3. 5. 4. 5] has been purified about 25-fold from the osmotic shock fluid of a constitutive mutant of Escherichia coli. The molecular weight of the enzyme is approximately 54, 000. High concentrations of urea reversibly inactivate cytidine deaminase activity, but do not cause the dissociation of the enzyme to smaller subunits.
The enzyme catalyzes the deamination of various amino-pyrimidine nucleosides with activity in the following order: deoxycytidine, fluorodeoxycytidine, 5-methyl-deoxycytidine, cytidine, and cytosine arabinoside. All deoxy- and ribonucleosides were found to inhibit the activity. Various heavy metal ions inhibit the enzyme, but sulfhydryl reagents including p-chloromercuribenzoate show no effect.View full abstractDownload PDF (450K) -
Effect of the 1, 4-Naphthoquinone Pigment, Xanthomegnin, on Oxidative Phosphorylation in Rat Liver MitochondriaYuki ITO, Kiyoshi KAWAI, Yoshinori NOZAWA1973 Volume 74 Issue 4 Pages 805-810
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSSome effects of a naphthoquinone pigment, xanthomegnin, isolated from Microsporum cookei on rat liver mitochondria were examined.
1. Polarographic monitoring of O2 consumption indicated that xanthomegnin is a strong uncoupler of oxidative phosphorylation in rat liver mitochondria.
2. The latent adenosinetriphosphatase [ATPase, EC 3. 6. 1. 3] activity of freshly prepared mitochondria was markedly stimulated by xanthomegnin; this stimulation was prevented by bovine serum albumin (BSA).
3. A large-amplitude swelling of isolated mitochondria was induced by xanthomegnin in isotonic KC1; addition of BSA suppressed this induction of mitochondrial swelling.View full abstractDownload PDF (398K) -
Nakatsugu YAGINUMA, Shigehisa HIROSE, Yuji INADA1973 Volume 74 Issue 4 Pages 811-815
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThe absorption or fluorescence spectrum of rhodamine 6G upon interaction with mitochondria was changed following the addition of substrate. A similar spectral change was obtained for the binding of positively charged rhodamine 6G to negatively charged chemicals such as sodium dodecyl sulfate, dextran sulfate, pentachlorophenol, and tetraphenylboron. This indicates that the positively charged dye molecules become exposed to the negatively charged region on the mitochondrial membrane generated by the addition of substrate, which may be closely associated with the charge separation of mitochondria.View full abstractDownload PDF (357K) -
Kumiko KAWAGUCHI, Kohei ISHIDATE, Kunio TAGAWA1973 Volume 74 Issue 4 Pages 817-826
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSA membranous preparation from anaerobically grown yeast cells was found to respire in the presence of NADPH. From the fact that this respiration is not sensitive to antimycin A but is strongly inhibited by CO, it appeared to be catalyzed via a non-mitochondrial electron transfer system involving P-450, resembling that of liver microsomes. The system was also found to involve a flavoprotein, NADPH-2, 6-dichlorophenolindophenol reductase, as the primary dehydrogenase. The preparation contained another CO-binding hemoprotein, P-420, but its involvement in the system
was ambiguous. Kinetic analysis revealed that heme-chelating reagents for P-450, such as CO and phenyl isocyanate, inhibit oxygen uptake competitively and, therefore, that the hemoprotein acts as a terminal oxidase. The possible physiological role of the electron transfer system involving P-450 was discussed in relation to lipid metabolism. However, since CO did not affect cell growth nor inhibit ergosterol synthesis and the desaturation of fatty acids under anaerobic conditions, it may be concluded that the system is not involved in the synthesis of ergosterol or in desaturation.View full abstractDownload PDF (766K) -
III. A Further Study on Polyinosinic Acid+Copolynucleotide of Cytidylic and Uridylic Acids, and Polycytidylic Acid+Copolynucleotide of Inosinic and Uridylic AcidsHideo AKUTSU, Motohiro FUKE, Hiroshi HASHIZUME1973 Volume 74 Issue 4 Pages 827-835
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSAn investigation of “helix-with-loops” structures of synthetic polynucleotide complexes by several methods including electron microscopy, sedimentation velocity, flow birefringence, and circular dichroism has been undertaken. We reached the conclusion that it is necessary to revise the model of “helix-with-loops” structure which was implicitly postulated before. In the revised structure, the “helix” structure is considered to be appreciably distorted from the regular double-helical structure and many “loops” are considered to form interchain bridges resulting in the formation of entangled networks.View full abstractDownload PDF (3069K) -
Bunmei INATSUKI, Masazumi HIRAGA, F. K. ANAN1973 Volume 74 Issue 4 Pages 837-848
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSThis is the first report of comparison of the biochemical properties of human thyroid mitochondria with those of animal tissues.
We isolated mitochondria, which appeared intact electron-microscopically, from the thyroid glands of patients with Graves' disease by digestion with protease (Nagarse) in modified SMEA medium. These mitochondria showed oxidation of TCA cycle intermediates, and also moderately high rates of oxidation of β-hydroxybutyrate and caproate, which have not been observed with mitochondria of normal human thyroid (Reinwein and Englhardt) or rat thyroid (Lehninger). The respiratory control ratio was 2-8 with α-ketoglutarate and β-hydroxybutyrate, 2-4 with succinate and caproate, and 1-2 with α-glycerophosphate or ascorbate plus TMPD as substrate. The ADP/O ratios obtained indicated the presence of three phosphorylation sites associated with the electron transport system. The effects of uncouplers, and energy transfer and respiratory chain inhibitors on human thyroid mitochondria were essentially similar to those observed with other mammalian mitochondria. The presence of a series of electron transport carriers in compatible amounts to those in heart mitochondria was revealed by difference spectroscopy. Our modified protease method yields mitochondria from human thyroid gland which are fairly intact judging from their morphological and biochemical properties.View full abstractDownload PDF (2037K) -
Kentaro IWASAKI, Kiyohisa MIZUMOTO, Michiko TANAKA, Yoshito KAZIRO1973 Volume 74 Issue 4 Pages 849-852
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (325K) -
Toshiko MATSUBARA, Akira HAYASHI1973 Volume 74 Issue 4 Pages 853-856
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (232K) -
Shoji ODANI, Tokuji IKENAKA1973 Volume 74 Issue 4 Pages 857-860
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (215K) -
Shigehiro HIRANO, Sumiyo KONDO1973 Volume 74 Issue 4 Pages 861-862
Published: October 25, 1973
Released on J-STAGE: November 18, 2008
JOURNAL FREE ACCESSDownload PDF (141K)
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