限制性核酸内切酶PstⅠ活性基团的研究  

Studies on the Active Groups of Pst I Restriction Endonuclease

作　　者：刘隽[1] 高成卓[2] 邹国林[2] 

机构地区：[1]河南职工医学院医学技术系,郑州450003 [2]武汉大学生命科学学院,武汉430072

出　　处：《河南科学》2009年第9期1077-1081,共5页Henan Science

基　　金：国家教育部博士点基金资助项目(1999048601)

摘　　要：分别以N-溴代琥珀酰亚胺(NBS)、2,3-丁二酮和N-乙基-5-苯基异噁唑-3’-磺酸盐作修饰剂,研究色氨酸、精氨酸残基和羧基对PstⅠ活性的影响.结果表明,NBS的修饰虽可导致PstⅠ活性丧失,但紫外吸收光谱和SDS-PAGE研究结果表明色氨酸残基并非PstⅠ的活性基团,而精氨酸残基和羧基的修饰可导致PstⅠ和PstⅠ*活性丧失,并按Keech和Farrant动力学方法分析得出无论在原活性还是星号活性条件下,有一个精氨酸残基和两个羧基是PstⅠ的活性基团.The chemical modification was studied with Nibromosuccinimide （NBS）, 2, 3-diacety Ⅰ and N-ethyl-pheny- lisoxazoliun-3＇-sulfonate as the modification reagents on its tryptophan, arginine residues and carboxyl group. It shows that the activity of Pst Ⅰcan be inhibited by NBS, and the results of ultraviolet absorption spectra and SDS- PAGE indicate that some tryptophan residues are active groups located at the surface of Pst I. Further-more, the modification of arginine residue and carboxyl group can make the enzyme prime and star activity lost. With the method provided by Keech and Farrant,the kinetic analysis demonstrates that one arginine and two carboxyl groups are active groups of Pst Ⅰ and Pst Ⅰ^＊.

关 键 词：Ⅱ型限制性核酸内切酶 活性基团 化学修饰 动力学 

分 类 号：Q556[生物学—生物化学]