Characterization of novel β-glucosidases with transglycosylation properties from Trichosporon asahii.

State Key Laboratory of Food Science and Technology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.

Journal of agricultural and food chemistry 2011 Oct 26

filter terms:

Two novel β-glucosidases from Trichosporon asahii, named BG1 and BG2, were purified to electrophoretic homogeneity using ammonium sulfate precipitation, hydrophobic interaction, ion exchange, and gelfiltration chromatography. The molecular weight of BG1 and BG2 were estimated as 160 kDa and 30 kDa, respectively. The K(m), V(max), K(cat), and K(cat)/K(m) values of the two β-glucosidases for p-nitrophenyl-β-D-glucopyranoside were determined. Both enzymes showed relatively high affinity to p-nitrophenyl-β-D-glucopyranoside in 4-nitrophenol glycosides and gentiobiose in saccharide substrates. The enzymes exhibited optimum activity at pH 6.0 and pH 5.5, respectively. Their respective optimum temperatures were 70 and 50 °C. Metal ions and inhibitors had different effects on the enzymes activities. Circular dichroism (CD) spectroscopy demonstrated that the purified BG1 exhibited a β-sheet-rich structure and that BG2 displayed a high random coil conformation. HPLC analysis of transglycosylation and reverse hydrolysis assays revealed that only BG1 possessed transglycosylation activity and synthesized cello-oligosaccharides by the addition of glucose. This suggested that BG1 could be used to produce complex bioactive glycosides and could be considered as a potential enzyme for industrial application.

Citation

Yuxia Wang, Jiming Li, Yan Xu. Characterization of novel β-glucosidases with transglycosylation properties from Trichosporon asahii. Journal of agricultural and food chemistry. 2011 Oct 26;59(20):11219-27