Novel substrate specificity of a membrane‐bound β‐glycosidase from the hyperthermophilic archaeon Pyrococcus horikoshii

FEBS Letters

Honda, Koichi²  Kawarabayasi, Yutaka¹  Kikuchi, Hisasi¹  Matsui, Ikuo²  Sakai, Yukihiro²  Matsui, Eriko² 

[1] National Institute of Technology and Evaluation, MITI, Nishihara, Shibuyaku, Tokyo, Japan;National Institute of Bioscience and Human-Technology, Tsukuba, Ibaraki 305, Japan

关键词: β-Glycosidase;    Thermophilic archaeon;    Membrane protein;    Thermostable enzyme;    Pyrococcus horikoshii;    BGPh;    β-glycosidase from Pyrococcus horikoshii;    BMPh;    a β-mannosidase gene homolog from P. horikoshii;    BGPf;    β-glucosidase from Pyrococcus furiosus;    BMPf;    β-mannosidase from P. furiosus;    Sβ-gly;    β-glycosidase from Sulfolobus solfataricus;    IPTG;    isopropyl-β-D-thiogalactopyranoside;    His-BGPh;    BGPh with His-tag;    SDS–PAGE;    sodium dodecyl sulfate–polyacrylamide gel electrophoresis;    X-Glu;    5-bromo-4-chloro-3-indolyl-β-glucopyranoside;    p-Nph-β-D-Glcp;    p-nitrophenyl-β-D-glucopyranoside;    LA-β-D-Glcp;    β-D-glucopyranosides with long alkyl chains;   

DOI  :  10.1016/S0014-5793(00)01156-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A β-glycosidase gene homolog of Pyrococcus horikoshii (BGPh) was successfully expressed in Escherichia coli. The enzyme was localized in a membrane fraction and solubilized with 2.5% Triton X-100 at 85°C for 15 min. The optimum pH was 6.0 and the optimum temperature was over 100°C, respectively. BGPh stability was dependent on the presence of Triton X-100, the enzyme's half-life at 90°C (pH 6.0) was 15 h. BGPh has a novel substrate specificity with k _cat/K _m values high enough for hydrolysis of β-D-Glcp derivatives with long alkyl chain at the reducing end and low enough for the hydrolysis of β-linked glucose dimer more hydrophilic than aryl- or alkyl-β-D-Glcp.

【 授权许可】

Unknown