SURFACE ELECTROSTATIC INTERACTIONS CONTRIBUTE LITTLE TO STABILITY OF BARNASE

被引：180

作者：

SALI, D ^{[1
]}

BYCROFT, M ^{[1
]}

FERSHT, AR ^{[1
]}

机构：

[1] UNIV CAMBRIDGE,CHEM LAB,CAMBRIDGE IRC PROT ENGN,MRC,PROT FUNCT & DESIGN UNIT,CAMBRIDGE CB1 2EW,ENGLAND

来源：

JOURNAL OF MOLECULAR BIOLOGY | 1991年 / 220卷 / 03期

关键词：

PROTEIN STABILITY; PROTEIN FOLDING; ELECTROSTATICS; SALT BRIDGES;

D O I：

10.1016/0022-2836(91)90117-O

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Electrostatic interactions are believed to play an important role in stabilizing the native structure of proteins. We have quantified the contribution to stability of an interaction between two oppositely charged side-chains on the surface of barnase. Using site-directed mutagenesis, glutamate 28 and lysine 32 were introduced onto the solvent-accessible side of the second α-helix in barnase. These two residues are separated by one turn of the helix, and so are ideally situated for their opposite charges to interact. Double mutant cycle analysis reveals that the interaction between Glu28 and Lys32 contributes only approximately 0.2 kcal/mol to stability of the protein. All other interations between exposed charged side-chains in barnase examined so far also contribute little to stability. We explain this low value by their location on the surface, rather than in the interior, of the protein. © 1991.

引用

页码：779 / 788

页数：10

共 33 条

[1] PH-INDUCED DENATURATION OF PROTEINS - A SINGLE SALT BRIDGE CONTRIBUTES 3-5 KCAL MOL TO THE FREE-ENERGY OF FOLDING OF T4-LYSOZYME [J].