標題: Effective induction, purification and characterization of Trichoderma koningii G-39 beta-xylosidase with high transferase activity
作者: Li, YK
Yao, HJ
Cho, YT
應用化學系
Department of Applied Chemistry
關鍵字: alpha-arabinosidase;configuration;retention;transxylosylation;beta-xylosides
公開日期: 1-Apr-2000
摘要: A beta-xylosidase was induced and purified from the culture filtrate of Trichoderma koningii G-39, grown in a medium containing 1% oat spelts xylan and 0.1% xylose, The presence of xylose unequivocally enhanced the induction of beta-xylosidase. The purified enzyme, which exhibited a significant alpha-arabinosidase activity, was obtained with high yield simply via ethanol precipitation and a single anion-exchange chromatography and was characterized as a monomeric glycoprotein with an estimated molecular mass of 104 kDa and a pl of 4.6. The K-m values towards P-nitrophenyl beta-D-xylopyranoside and p-nitrophenyl alpha-L-arabinopyranoside are 0.04 and 7.5 mM, respectively. It is stable at pH 2.5-7.4, 37 degrees C. The pH and temperature optima are in the range of 3.5-4.0 and 55-60 degrees C, respectively. Contrary to most beta-xylosidases from other sources, Hg2+ (up to 25 mM) has no effect on enzyme activity. Xylose was shown to inhibit the purified enzyme with a moderate Ki value of 5 mM, The enzyme exhibited transxylosylation activity and was characterized as a 'retaining' enzyme, catalysing the hydrolysis of substrate with the retention of anomeric configuration.
URI: http://dx.doi.org/10.1042/BA19990072
http://hdl.handle.net/11536/30609
ISSN: 0885-4513
DOI: 10.1042/BA19990072
期刊: BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY
Volume: 31
Issue: 
起始頁: 119
結束頁: 125
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