A highly selective ginsenoside Rb-1-hydrolyzing beta-D-glucosidase from Cladosporium fulvum

作者：Gao, Juan; Zhao, Xuesong; Liu, Haibo; Fan, Yuying; Cheng, Hairong; Liang, Fei; Chen, Xingxing; Wang, Nan; Zhou, Yifa^*; Tai, Guihua

来源：Process Biochemistry, 2010, 45(6): 897-903.

DOI：10.1016/j.procbio.2010.02.016

• beta-Glucosidase
• Cladosporium falvum (syn. Fulvia fulva)
• Ginsenoside Rb-1
• Ginsenoside Rd
• Biotransformation
• Selectivity

G-I, a highly selective beta-glucosidase, was purified from phytopathogenic fungus Cladosporium fulvum (syn. Fulvia fulva). G-I was a monomer with native molecular weight of 85 kDa and pI value of 4.2. The maximal activity to p-nitrophenyl-beta-D-glucopyranoside (pNPG) occurred at pH 6.0 and 45 degrees C at which the K, against pNPG was 0.18 mM and V-max was 46.7 mu mol nitrophenol/min/mg. G-I was highly stable within pH 4.0-11.0 and below 40 degrees C. It was inhibited by Co2+, Cu2+ and Zn2+ (50 mM), but showed resistance to sodium dodecyl sulfonate (SDS, 250 mM). G-I was highly active against beta-linked disaccharide cellobiose, gentiobiose and sophorose, but exhibited very low activities against other aryl-glycosides, methyl-alpha-glycosides and clisaccharides trehalose and sucrose. Moreover. G-I specifically hydrolyzed beta-(1 -> 6)-glucosidilc linkage at the C-20 site of ginsenoside Rbi to produce ginsenosidle Rd, without attack on other beta-D-glucosidic linkages. The oligopeptide fragments of G-I were sequenced by nanoESI-MS/MS and showed similarity to the sequences from the glycoside hydrolase family 3. G-I is different to G-II (a glycosidase previously purified from the same fungus) in composition and molecular weight. It shows more stable and higher selectivity than G-II.

• 出版日期2010-6
• 单位辽宁工程技术大学; 东北师范大学