海洋假单胞杆菌QD80低温碱性蛋白酶的化学修饰  

Chemical Modification of Marine Pseudomonas QD80 Cold Alkaline Protease

作　　者：郝建华[1] 王跃军[1] 袁翠[1] 孙谧[1] 

机构地区：[1]中国水产科学研究院黄海水产研究所海洋酶工程室,山东青岛266071

出　　处：《应用与环境生物学报》2006年第3期371-374,共4页Chinese Journal of Applied and Environmental Biology

基　　金：国家十五863项目(2003AA625070);农业部海洋与河口渔业重点开放实验室开放课题(K-2-04-16)联合资助~~

摘　　要：海洋假单胞杆菌QD80低温碱性蛋白酶(QDAPr)具有良好的低温适应性,且与常见的增稠剂及表面活性剂有良好的配伍性.因此该蛋白酶在日用化学领域,尤其是低温洗涤领域,具有广泛的应用价值.为研究其结构与功能之间的关系,用EDC、PMSF、N-AI、2,3-丁二酮等8种化学修饰剂修饰该低温碱性蛋白酶,然后检测残余酶活力,借以研究酶分子中氨基酸侧链基团与酶活性中心的关系.结果表明,羧基、丝氨酸、ε-氨基、巯基等残基与酶活性无关;而色氨酸、组氨酸、酪氨酸残基侧链的化学修饰引起酶活性的大幅度下降,说明色氨酸、组氨酸、酪氨酸残基是酶活力所必需的基团.精氨酸残基侧链的化学修饰引起酶活性的轻微下降,说明精氨酸对酶活性具有一定贡献,但不处于活性中心.The cold alkaline protease of marine Pseudomonaa QD80 （QDAPr） has good adaptability to low temperature, and fine compatibility with the common thickener and surfaetant. So it is widely used in chemical industry for daily use, especially in cold washing sector. In order to investigate the relationship of structure and function of QDAPr, 8 chemical modifiers, such as EDC, PMSF, N-AI and 2,3-diacetyl, were used to modify the QDAPr. The protease was not affected by EDC, PMSF, 2-ME and acetic anhydride, indicating that carboxyl groups, serine residues, guanidine groups and ε-amino groups were inessential to the enzyme activity. The enzyme activity was significantly decreased after BrAc, NBS and N-AI modification. These results indicated that the histidine residues, tryptophane residues and tyrosine residues were essential to catalytic activity or located at the active site of QDAPr. The enzyme activity was slightly decreased after 2,3-diacetyl modification, which indicated the arginine residues were nonessential to catalytic activity, but would affect enzyme activity. Fig 5, Tab 2, Ref 18

关 键 词：海洋假单胞杆菌 低温碱性蛋白酶 化学修饰 

分 类 号：Q936[生物学—微生物学]