β-Glucoside metabolism in Oenococcus oeni: Cloning and characterisation of the phospho-β-glucosidase bglD
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- 作者：A. Capaldo ; M.E. Walker ; C.M. Ford ; V. Jiranek
- 关键词：Phospho-β ; -glucosidase ; Oenococcus oeni ; Phosphoenolpyruvate-phospho transferase system
- 刊名：Food Chemistry
- 出版年：2011
- 出版时间：15 March 2011
- 年：2011
- 卷：125
- 期：2
- 页码：476-482
- 全文大小：1030 K
文摘
The structural gene for a phospho-β-glucosidase from the oenologically important lactic acid bacterium (LAB) Oenococcus oeni has been cloned and its protein product characterised. This gene is found in a putative β-glucosidase operon of 2178 base pairs encoding 4 genes designated bglA to bglD. The bglA, B and C genes were not cloned and characterised, however, are thought to be phosphoenolpyruvate dependent phospho transferase system (PEP-PTS) components IIC, IIA and IIB which regulate the uptake, phosphorylation and translocation of β-glucosides across the cytoplasmic membrane. The cloned bglD was sequenced and expressed in Escherichia coli followed by purification. The purified bglD protein has 480 residues, a molecular mass of 55.5 kDa and shows high homology to known phospho-β-glucosidases. bglD exhibited high activity towards the phosphorylated β-glucoside para-nitrophenol-β-d-glucopyranoside-6-phosphate with a pH optimum of 5.5 and maintained similar levels of activity between temperatures of 4 °C and 40 °C. The enzyme was not active against non-phosphorylated β-glucosides.