Purification and characterization of furostanol glycoside 26‐O‐β‐glucosidase from Costus speciosus rhizomes

FEBS Letters

Ebizuka, Yutaka¹  Inoue, Kentaro¹ 

[1] Department of Pharmacognosy and Phytochemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan

关键词: Furostanol glycoside;    Spirostanol glycoside;    β-Glucosidase;    Postharvest hydrolysis;    F26G;    Costus speciosus Sm;    EGME;    ethylene glycol monomethyl ether;    F26G;    Furostanol glycoside 26-O-β-glucosidase;    HPLC;    high performance liquid chromatography;    IC 50;    50% inhibition concentration;    pNP;    p-nitrophenol;    pNPG;    p-nitrophenyl β-d-glucoside;    SDS-PAGE;    sodium dodecylsulfate polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(95)01447-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In plants, spirostanol glycosides (steroid saponins) are known to be formed from furostanol glycosides during postharvest treatment and storage. Furostanol glycoside 26-O-β-glucosidase (F26G) involved in this conversion was purified to apparent homogeneity for the first time from Costus speciosus rhizomes which accumulate these glycosides. The enzyme was highly specific for cleavage of the C-26-bound glucose moiety of furostanol glycosides showing K _m for protogracillin of 50 μM. Glucono-1,5-lactone, a typical β-glucosidase inhibitor, and diosgenin, an aglycone of spirostanol glycosides, strongly inhibited the enzyme activity. The purified F26G is dimeric with a native apparent molecular weight of 110,000 consisting of subunits of 54,000 and 58,000. The N-terminal sequence of the 54,000 protein has a high similarity to the sequences found in N-terminal regions of known plant β-glucosidases.

【 授权许可】

Unknown