生物加工过程2013，Vol.11Issue(3)：52-58,7.DOI:10.3969/j.issn.1672-3678.2013.03.010
链霉菌壳聚糖酶的纯化及其酶学性质
Purification chitosanase from Streptomyces hygroscopious and its catalytic properties
摘要
Abstract
The chitosanase purified from Streptomyces hygroscopious isolated from the offshore in Yantai,and then properties of chitosanase were investigated to provide a theoretical basis for its application.The crude enzyme of chitosanase was extracted by ammonium sulfate fraction precipitation,and two types of enzyme,(ChA and ChB),were obtained by gel filtraction chromatography with Sephadex G-100.The catalytic properties of ChA were further studied.The molecular weight of ChA is 41.6 kDa,which was mono-unit protein,and the maximum UV absorbances were at 220 nm and 280 nm.The optimum pH of ChA was 5.0-5.5 when chitosan was used as substrate and the optimum temperature was 55 ℃.Thermal stability experiment showed that 33.3％ of activity was retained after heating at 30℃ for 1 h,22.2％ of activity was retained after heating at 40 ℃ for 1 h.The initial reaction rate of ChA was 6.2 × 10-3μ mol/(mL· min),the maximum rate was 0.318 μ mol/(mL· min),and the Michaelis constant Km was 1.0 × l0-2mg/mL.Furthermore,ChA showed relative substrate specificity.K +,Na +,Li +,Mg2 +,Ca2 +,Ba2 +,Zn2 +,Cu2 +,and Co2 + had labile effects on the enzyme,while Mn + could activate the enzyme.The heavy metal ions Hg2 +,Pb2 +,Ag +,and Cd2 + inhibited the enzyme activity.Mn2 + could make a mixed activation effect on the enzyme,but Zn2+ displayed a competitive inhibition on the enzyme.关键词
酶学性质/壳聚糖酶/分离纯化/链霉菌Key words
catalytic property / chitosanase / bioseparation / Streptomyces hygroscopious分类
生物科学引用本文复制引用
杨立红,程仕伟,冯志彬,周楠楠,孔云红,明永飞..链霉菌壳聚糖酶的纯化及其酶学性质[J].生物加工过程,2013,11(3):52-58,7.基金项目
山东省高等学校科技计划(J12LD02) （J12LD02）
鲁东大学科研基金(LY20083305) （LY20083305）
