合成T4溶菌酶基因活性位点残基的突变及其对裂解活性的影响。

Mutation of active site residues in synthetic T4-lysozyme gene and their effect on lytic activity.

作者信息

Anand N N, Stephen E R, Narang S A

机构信息

Division of Biological Sciences, National Research Council of Canada, Ottawa.

出版信息

Biochem Biophys Res Commun. 1988 Jun 16;153(2):862-8. doi: 10.1016/s0006-291x(88)81175-6.

DOI:10.1016/s0006-291x(88)81175-6

PMID:3382407

Abstract

The active site amino acids (Glu11 and Asp20) in T4-lysozyme have been mutated to their isosteric residues Gln or Asn and/or acidic residues such as Glu----Asp or Asp----Glu by the oligonucleotide-replacement method. Out of eight mutants so generated the mutant T4-lysozyme obtained from pTLY.Asp11 retains maximum amount of activity (approximately 16%), pTLY.Asn20 the least (0.9%) whereas pTLY.Gln11 lost completely. A systematic study of the active and inactive mutants thus generated supports the important role of Glu11 and Asp20 in T4-lysozyme activity as predicted in earlier studies.

摘要

通过寡核苷酸置换法，已将T4溶菌酶中的活性位点氨基酸（Glu11和Asp20）突变为它们的等排残基Gln或Asn，和/或酸性残基，如Glu→Asp或Asp→Glu。在如此产生的八个突变体中，从pTLY.Asp11获得的突变体T4溶菌酶保留了最大量的活性（约16%），pTLY.Asn20保留的活性最少（0.9%），而pTLY.Gln11则完全丧失了活性。对如此产生的活性和非活性突变体的系统研究支持了Glu11和Asp20在T4溶菌酶活性中所起的重要作用，这与早期研究中的预测一致。