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Volume 55, Issue 2
Displaying 1-10 of 10 articles from this issue
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Mitsuo YAMAZAKIArticle type: Article
1981 Volume 55 Issue 2 Pages 73-84
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
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Junzo HASEGAWA, Tsutomu TANAKA, Kiyoshi WATANABEArticle type: Article
1981 Volume 55 Issue 2 Pages 85-90
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSThe activity of CN-B_<12> for Escherichia coli 215 was lost by incubating the compound with the cultured broth of Streptomyces nitrosporeus. UV absorption spectra of inactivated corrinoid (SA) were very similar to that of CN-B CN-B_<12> With the only exception of an absorption peak at 1,725 cm^<-1>. SA was a mono-carboxylic acid of CN-B CN-B_<12>, but its behaviors in PPC, PEP and TLC did not agree with those of the known CN-B CN-B_<12> monocarboxylic acids. When SA was hydrolyzed with 0.lN HCl at 370℃ for 64 h, a tetracarboxylic acid containing the lower ligand was obtained. From the above results and elementary analysis, it was concluded that SA was a new CN-B CN-B_<12> monocarboxylic acid possessing an acetic acid group in place of an acetamide group which had never been obtained.View full abstractDownload PDF (591K) -
Junzo HASEGAWAArticle type: Article
1981 Volume 55 Issue 2 Pages 91-96
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSA new cyanocobalamin monocarboxylic acid (SA) possessing an acetic acid group in place of an acetamide group prepared from cyanocobalamin (CN-B_<12>) with an enzyme in Streptomyces nitrosporeus was active as a vitamin B_<12> antagonist for E. coli 215, a vitamin B_<12> by auxotroph. The compound was amidated by chemical and biological methods. SA was converted to CN-B_<12> by amidation with dry ammonia under the anhydrous condition, and when incubated with the cells of Pr. shermanii, three forms of corrinoids, SA, adenosyl-SA and DBCC, were found in the cells. However, CN-B_<12> was not observed. It was thus confirmed that this nucleotide-containing monocarboxylic acid of corrinoid could be utilized as a precursor of vitamin B12 biosynthesis by Pr. shermanii.View full abstractDownload PDF (554K) -
Purification and Characterization of Pyridoxal Kinase from Vitamin B_6 Auxotroph of Escherichia coliYoshiko FURUKAWAArticle type: Article
1981 Volume 55 Issue 2 Pages 97-105
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSPyridoxal kinase was purified from Escherichia coli KG 980 by ammonium sulfate fractionation, and successive chromatographies on DEAE-cellulose, Sephadex G-150 and pyridoxamine (PM)-Sepharose. The overall purification was about 2,500-fold over the crude extract with an yield of about 23%. Polyacrylamide gel electrophoresis indicated that the final product was 70 to 75% homogeneous. The molecular weight of the enzyme was estimated to be 47,000 by Sephadex G-100 gel filtration and 58,000 by SDS polyacrylamide gel electrophoresis. From isoelectric gel electrophoresis, an isoelectric point of 4.8 was estimated. The K_m values for pyridoxine (PN), pyridoxal (PL) and PM were 9.1 × 10^<-6>M, 1.3 × l0^<-4>M and 4.2 × 10^<-4>M, respectively. The relative V_<max> values obtained for PN, PL and PM were 100%, 70% and 170%, respectively. The pH optimum was 6.0 with PN or PL and 7.0 with PM as the substrate. PM, 4-deoxypyridoxine (dPN) and 5'-dPN showed competitive inhibition for phosphorylation of PN with Ki values of 4.4 × l0^<-4>M, 2.5 × l0^<-5>M and 2.9 × l0^<-4>M, respectively. Pyridoxal 5'-phosphate showed noncompetitive inhibition with Ki Value of 9.1 × 10^<-4>M. PL and 5'-deoxypyridoxal (dPL) were both competi-tive and noncompetitive inhibitors for PN. The K_i Values of PL was 1.4 × 10^<-4>M (as a competitive inhibitor) and 5.9 × l0^<-5>M (as a noncompetitive inhibitor), and the K_i Values of 5'-dPL was 2.5 × l0^<-4>M (as a competitive inhibitor) and 3.8 × 10^<-5>M (as a noncompetitive inhibitor).View full abstractDownload PDF (936K) -
Yoshiko FURUKAWAArticle type: Article
1981 Volume 55 Issue 2 Pages 107-113
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSPyridoxal kinase from Escherichia. coli KG 980 was inactivated by pyridoxal (PL) as follows : 1) The inactivation of the enzyme was reversible. The inactivation showed an equilibrium reaction pattern with K_<eq> values of 37 to 31 mM^<-1>. 2) The inactivation followed pseudo-first order kinetics with respect to time, and then maximal inactivation was achieved by incubation for 15〜20 min. 3) The results were consistent with a one-step inactivation mechanism. 4) The inactivation was due to the specific binding of PL to one crucial PL binding site, by the formation of Schiff base. 5) The substrate (or analog) did not protect against inactivation with PL. 6) The binding of PL was accompanied by the complete loss of enzyme activity.View full abstractDownload PDF (650K) -
Article type: Appendix
1981 Volume 55 Issue 2 Pages 115-118
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
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[in Japanese]Article type: Article
1981 Volume 55 Issue 2 Pages 119-120
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSDownload PDF (316K) -
[in Japanese]Article type: Article
1981 Volume 55 Issue 2 Pages 120-121
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSDownload PDF (333K) -
[in Japanese]Article type: Article
1981 Volume 55 Issue 2 Pages 121-122
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSDownload PDF (298K) -
[in Japanese]Article type: Article
1981 Volume 55 Issue 2 Pages 122-123
Published: February 25, 1981
Released on J-STAGE: March 09, 2018
JOURNAL FREE ACCESSDownload PDF (232K)
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