鸭疫里默氏杆菌明胶酶的纯化及特性分析

为阐明鸭疫里默氏杆菌明胶酶的特性,试验以液化明胶的AF株为研究对象,纯化了其明胶酶,并对该酶进行热稳定性、蛋白化学修饰剂抑制作用、金属离子及络合物的影响和致病性等特性分析。结果表明,鸭疫里默氏杆菌AF株的培养上清经超滤浓缩、70%硫酸铵沉淀、阴离子交换层析、疏水柱层析和凝胶柱层析,可获得纯化的明胶酶,SDS-PAGE显示单条带,相对分子质量约59000。该酶在65℃迅速失活,Cu2+、Cd2+、Mn2+、Hg2+对酶活性有强烈的抑制作用,络合物EDTA和EGTA的抑制作用可被Ca2+逆转,PMSF、NBS和AAD可抑制其活性。明胶酶对雏鸭具有毒力,能缩短鸭疫里默氏杆菌致病菌株感染的潜伏期和致死动物的时间,显著提高动物的死亡率。以上结果表明,鸭疫里默氏杆菌明胶酶是一种具有致病作用的金属蛋白酶。

Purification and Characterization of Gelatinase from Riemerella anatipestifer Strain AF

To ascertain the nature of gelatinase and its role in the pathogenesis of R.anatipestifer,the enzyme from R.anatipestifer strain AF,was purified and its characterizations were analyzed,including stability for heat,effects of proteases inhibitors and metal ions on its activities and pathogenicity for ducklings.The results revealed that gelatinase was purified from the culture supernatant of R.anatipestifer strain AF by ultrafiltration,70% ammonium sulfate precipitation,anion exchange chromatography,hydrophob...