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Novel substrate specificity of a membrane‐bound β‐glycosidase from the hyperthermophilic archaeon Pyrococcus horikoshii
Author(s) -
Matsui Ikuo,
Sakai Yukihiro,
Matsui Eriko,
Kikuchi Hisasi,
Kawarabayasi Yutaka,
Honda Koichi
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01156-x
Subject(s) - pyrococcus horikoshii , chemistry , alkyl , hydrolysis , substrate (aquarium) , escherichia coli , dimer , enzyme , membrane , biochemistry , stereochemistry , organic chemistry , biology , gene , ecology
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 ‐Glc p 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 ‐Glc p .