SYNTHETIC REACTION OF CELLVIBRIO-GILVUS CELLOBIOSE PHOSPHORYLASE

被引：46

作者：

KITAOKA, M ^{[1
]}

SASAKI, T ^{[1
]}

TANIGUCHI, H ^{[1
]}

机构：

[1] NATL FOOD RES INST,TSUKUBA,IBARAKI 305,JAPAN

来源：

JOURNAL OF BIOCHEMISTRY | 1992年 / 112卷 / 01期

关键词：

D O I：

10.1093/oxfordjournals.jbchem.a123862

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The synthetic reactions of the cellobiose phosphorylase from Cellvibrio gilvus were investigated in detail.It was found that, besides D-glucose, some sugars having substitution or deletion of the hydroxyl group at C2 or C6 of the D-glucose molecule could serve as a glucosyl acceptor, though less effectively than D-glucose. The enzyme showed higher activity with beta-D-glucose than with the alpha-anomer as an acceptor. This result indicates that it recognizes the anomeric hydroxyl group not involved directly in the reaction. beta-D-Cellobiose was also phosphorolyzed faster than the alpha-anomer. Substrate inhibition was observed with D-glucose, 6-deoxy-D-glucose, or D-glucosamine as an acceptor, with D-glucose being most inhibiting. This inhibition was studied in detail and it was found that D-glucose competes with alpha-D-glucose-1-phosphate for its binding site. A model of competitive substrate inhibition was proposed, and the experimental data fit well to the theoretical values that were calculated in accordance with this model.

引用

页码：40 / 44

页数：5

共 25 条

[1] SYNTHESIS OF 4-O-BETA-D-GLUCOPYRANOSYL-D-XYLOSE 4-O-BETA-D-GLUCOPYRANOSYL-D-ARABINOSE 4-O-BETA-D-GLUCOPYRANOSYL-2-DEOXY-D-GLUCOSE 4-O-BETA-D-GLUCOPYRANOSYL-D-MANNOSE AND 4-O-BETA-D-GLUCOPYRANOSYL-D-GLUCOSAMINE BY CELLOBIOSE PHOSPHORYLASE FROM CLOSTRIDIUM THERMOCELLUM [J].