All issues
Volume 44 (1971)
- Issue 6 Pages 295-
- Issue 5 Pages 231-
- Issue 4 Pages 185-
- Issue 3 Pages 121-
- Issue 2 Pages 69-
- Issue 1 Pages 1-
Volume 44, Issue 6
Displaying 1-5 of 5 articles from this issue
- |<
- <
- 1
- >
- >|
-
Fumio KAWAIArticle type: Article
1971 Volume 44 Issue 6 Pages 295-302
Published: December 25, 1971
Released on J-STAGE: February 27, 2018
JOURNAL FREE ACCESSThe biosynthesis of the pteridine moiety from guanine nucleotides was investigated in green leaves by following its enzymatic conversion to dihydropteroic acid. Various synthetic substances were compared for their efficacy of being incorporated into dihydropteroic acid in the presence of cell free system from green leaves ; the substances chosen were those having been supposed by Weygand et al. in insects and those postulated by others in microorganisms to serve as intermediates in the biosynthesis of the pteridine. The experimental results allowed to postulate that the pathway from guanine nucleotides to dihydropteroic acid in green leaves involves the reaction sequence ; guanine nucleotides→2-amino-4-hydroxy-6-(D-erythrotrihydroxypropyl) dihydropteridine→2-amino-4-hydroxymethyldihydropterid ine→its pyrophosphate ester. Adenosine triphosphate, magnesium ion and p-aminobenzoate were found as essential factors in these conversion reactions. Additional evidences supporting the postulated pathway were provided from the inhibition studies ; the analogs closely related to the substrates were found to inhibit the reaction acting respectively on different three steps in the reaction sequence. The biosynthetic pathway of the pteridine in green leaves are postulated which is essentially indifferent from that having been established for the microbial system.View full abstractDownload PDF (793K) -
Tatsuo OZAWA, Shinichi SAITO, Isao TOMITAArticle type: Article
1971 Volume 44 Issue 6 Pages 303-307
Published: December 25, 1971
Released on J-STAGE: February 27, 2018
JOURNAL FREE ACCESSTransketolase (D-sedoheptulose-7-phosphate, D-glyceraldehyde-3-phosphate glycolaldehyde transferase E. C. 2. 2. 1. 1) has been purified from brewer's yeast according to the method of P. Srere et al. and the resolution for thiamine pyrophosphate and divalent cations has been efficiently carried out using 0.025_M glycylglycine buffer (pH7.6). Coenzyme reconstitution for the enzyme was promoted by incubating at 30℃. Thiamine pyrophosphate alone, without added divalent cation, could activate apoenzyme and was irresistibly bound to reconstitute holoenzyme. 2'-nor-Thiamine and 2'-ethylthiamine pyrophosphate showed negligible and 8%activities as the coenzymes respectively.View full abstractDownload PDF (544K) -
Tatsuo OZAWA, Shinchi SAITO, Isao TOMITAArticle type: Article
1971 Volume 44 Issue 6 Pages 308-312
Published: December 25, 1971
Released on J-STAGE: February 27, 2018
JOURNAL FREE ACCESSThe activation of brewer's yeast apotransketolase with divalent cations was observed effectively in a low thiamine pyrophosphate concentration. Relative activities were observed in the order of Ca^<2+>>Mn^<2+>>Mg^<2+>>Cd^<2+> and no activity with Zn^<2+>, Cu^<2+>. Holotransketolase which was reconstituted with Ca^<2+> or Mn^<2+> showed negligible resolution in gelfiltration (Sephadex G-25), but that reconstituted with Mg^<2+> or Cd^<2+> lost their original activities in gelfiltration and reactivated by the incubation with thiamine pyrophosphate and Mg^<2+> as high as 38%, 51% respectively. The inhibition of transketolase with Zn^<2+> was removed by means of gelfiltration, while that with Cu^<2+> was not removable.View full abstractDownload PDF (466K) -
Kazuma MIYAJI, Toshio AKIYAMA, Tsuneo NORO, Keiko MIZOGUCHIArticle type: Article
1971 Volume 44 Issue 6 Pages 313-318
Published: December 25, 1971
Released on J-STAGE: February 27, 2018
JOURNAL FREE ACCESS^<35>S-Thiamine or ^<35>S-0-nicotinylthiamine disulfide was administered orally to mice with liver injury due to CCl_4. There was decrease in liver uptake in respect to control. After ^<35>S-O-nicotinylthiamine disulfide was treated liver uptake decreased first, but as compared to control, markedly increased in 24 hours. When O-nicotinylthiamine disulfide was given 500mg to patients with liver damage, there was, as compared to patients with other disease, greater urinary excretion of vitamin B_1 in 24 hours.View full abstractDownload PDF (464K) -
Kazuma MIYAJI, Hideo KASHIWAGI, Toshio AKIYAMAArticle type: Article
1971 Volume 44 Issue 6 Pages 319-323
Published: December 25, 1971
Released on J-STAGE: February 27, 2018
JOURNAL FREE ACCESSO-Nicotinylthiamine disulfide was administered to patients with impaired pulmonary function in a dosis of 125mg per day (equivalent of B_1・HCl) for 4 weeks. There was no change in red blood count, white blood count, zinc sulfate test, total cholesterol, serum-GOT and serum-GPT, slight decrease in hemoglobulin and serum protein, and mere increase in albumin globulin ratio, alkaline phosphatase and LDH.View full abstractDownload PDF (394K)
- |<
- <
- 1
- >
- >|