All issues
Volume 62, Issue 7
Displaying 1-11 of 11 articles from this issue
- |<
- <
- 1
- >
- >|
-
Miyako TANAKA, Yoshikazu IZUMI, Hideaki YAMADAArticle type: Article
1988 Volume 62 Issue 7 Pages 305-315
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSStudies on the biosynthesis and biodegradation of biotin and their regulation in microorganisms are reviewed. The pathway of biotin biosynthesis is as follows : pimelic acid → pimelyl-CoA → 7-keto-8-aminopelargonic acid → 7, 8-diammopelargomc acid- dethiobiotin → biotin. All the enzymes involved in the reactions from pimelic acid to dethiobiotin were characteried and found to be regulated by biotin through feedback repression. Mycoplana sp. No. 166 having the highest biotin-degrading ability was isolated from soil. The metabolites from biotin and dethiobiotin were isolated and identified by mass and NMR spectral analyses. New biotin and dethiobiotin metabolites found were β-hydroxybisnorbiotin, β-hydroxydethiobiotin, and tetranordethiobiotinyl ketone. These results indicated that the degradation of biotin is initiated by β-oxidation of its side chain. Biotinyl-CoA synthetase, the first enzyme involved in β-oxidation of the side chain; was purified to homogeneity. The enzyme was a monomeric enzyme with a molecular weight and an isoelectric point of about 55,000 and 4.85, respectively. The purified enzyme catalyzed stoichiometric conversion of biotin, ATP, and CoA into biotinyl-CoA, AMP, and PPi. Dethiobiotin and actithiazic acid, a synthetic biotin analog, were also effective as substrates. Biotinyl-CoA could be used as substrate for acyl-CoA oxidase and α-dehydrobiotinyl-CoA was produced. The authors attempted to establish the production of α-dehydrobiotin and the enzymatic determination of biotin using two enzymes, biotinyl-CoA synthetase and acyl-CoA oxidase. A mutant strain of Bacillus sphaericus. AB 12, resistant against actithiazic acid and 5-(2-thienyl)-valeric acid was obtained and found to excrete biotin 7.1 times as much as the wild type strain. Recent studies progressed on biotin production by bacteria transformed by recombinant DNA, are also reviewed.View full abstractDownload PDF (1149K) -
Nutritional Studies of Ascorbic Acid with a Rat Mutant Unable to Synthesize Ascorbic Acid (ODS Rat).Fumihiko HORIO, Akira YOSHIDAArticle type: Article
1988 Volume 62 Issue 7 Pages 317-333
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESS1. ODS-od/ od rats (ODS rats) hereditarily unable to synthesize ascorbic acid have no hepatic L-gulonolactone oxidase activity. In ODS rats, the dietary requirement of ascorbic acid to maintain normal growth and to prevent scurvy is about 300 mg per kilogram diet. 2. In normal rats able to synthesize ascorbic acid, the administration of several types of xenobiotics caused a marked increase in urinary excretion of ascorbic acid and in the concentrations (of ascorbic acid) in various tissues. The administration of xenobiotics increased the biosynthesis of ascorbic acid in liver, and accelerated concomitantly the turnover of ascorbic acid in body. In guinea pigs unable to synthesize ascorbic acid, the dietary requirement of ascorbic acid was increased severalfold for improving the growth depression and the mortality due to xenobiotics, such as PCB. In ODS rats, the dietary requirement of ascorbic acid was increased several-fold by the administration of xenobiotics for the maximum induction of hepatic drug-metabolizing enzymes. 3. Acute ascorbic acid deficiency caused a hypercholesterolemia and an elevation of hepatic concentration of cholesterol due to the deppression of bile acid synthesis in ODS rats fed a cholesterol-containing diet or a PCB-containing diet. Moreover, the concentration of LDL-cholesterol in serum was higher in ascorbic acid-deficient ODS rats than in ODS rats fed a diet supplemented with an appropriate amount of ascorbic acid.View full abstractDownload PDF (1714K) -
Effect of Thiamin and Its Analogues on Growth and Thiaminase II Activity of Bucillus aneurinolyticusToshiyuki NAKATSUKA, Kiroku SUZUKI, Yoshihisa NAKANO, Shozaburo KITAOK ...Article type: Article
1988 Volume 62 Issue 7 Pages 335-341
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSSpecific activity of thiaminase II reached 150nmol/ min/mg protein at the logarithmic growth phase, when B. aneurinolyticus was grown in a medium containing 0.1μM thiamin or 2-methyl-4-amino-5-hydroxymethylpyrimidine (OMP). The thiaminase II activity from cells grown in the medium containing 3μM thiamin or OMP was 0.6% Of that in the 0.1μM thiamin or OMP medium, while in the medium containing 0.3μM thiamin or OMP the growth was 1.7 times as high as that at 0.1μM thiamin or OMP. Similar effect was observed in thiamin-analogues, quinolinothiamin, heteropyrithiamin, dimethialium and pyrithiamin, but oxythiamin, amprolium, pyrimidinylcysteine, pyrimidinylthiophenol and thiazole were not effective. After thiamin, OMP or thiamin-analogues effective for the growth was taken up by the cells, 80 to 95% Of intracellular thiamin occurred as thiamin pyrophosphate. The increase of thiaminase II activity, when B. aneurinolyticus was grown in the 0.1μM thiamin medium, was completely repressed by chloramphenicol.View full abstractDownload PDF (650K) -
Katsumi SHIBATA, Hiroko MATSUO, Kazuo IWAIArticle type: Article
1988 Volume 62 Issue 7 Pages 343-348
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSHuman urine was collected 5 hr after lunch for 3 months and the urinary excretion of N^1-methylnicotinamide (MNA) , N^1-methyl-2 pyridone-5-carboxamide (2-py) and N^1-methyl-4-pyridone-3-carboxamide (4-Py), which are used as a biochemical index of niacin nutrition, were measured by high-performance liquid chromatography. The correlation between niacin equivalent intake at lunch and each of the following items- MNA, 2-Py, 4-Py or " MNA+2-py+4-py " excretion, the 2-Py/ MNA, 4-Py/ MNA, 2-Py+4-py/ MNA or 2-Py/ 4-Py ratio was not significant. In terms of niacin equivalent intake per 1000kcal, no significant correlation was observed. The daily urinary excretions of MNA, 2-Py and 4-Py were very fluctuating even in the same individual. These results indicate that urinary excretion of MNA, 2-Py and 4-Py does not immediately change with food taken at lunch, and that these excretions would be affected by the unknown factors or by long term food intakes. But, when a large amount of nicotinamide (100mg) was administered at lunch, urinary excretion of MNA, 2-Py and 4-Py, 5 hr after lunch, increased markedly. Therefore, when these values are used as a biochemical index of niacin nutrition, it is a very dangerous to decide with only one-time value; it should be decided from the mean value of the values measured at least 4 times at intervals of one week.View full abstractDownload PDF (587K) -
Article type: Appendix
1988 Volume 62 Issue 7 Pages 349-353
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (471K) -
[in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 355-356
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (303K) -
[in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 356-357
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (269K) -
[in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 358-360
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (406K) -
[in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 360-361
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (306K) -
[in Japanese], [in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 362-364
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (423K) -
[in Japanese], [in Japanese]Article type: Article
1988 Volume 62 Issue 7 Pages 364-365
Published: July 25, 1988
Released on J-STAGE: March 16, 2018
JOURNAL FREE ACCESSDownload PDF (204K)
- |<
- <
- 1
- >
- >|