Contribution of hydrophobic interactions to protein stability.


Abstract

A major factor in the folding of proteins is the burying of hydrophobic side chains. A specific example is the packing of alpha-helices on beta-sheets by interdigitation of nonpolar side chains. The contributions of these interactions to the energetics of protein stability may be measured by simple protein engineering experiments. We have used site-directed mutagenesis to truncate hydrophobic side chains at an alpha-helix/beta-sheet interface in the small ribonuclease from Bacillus amyloliquefaciens (barnase). The decreases in stability of the mutant proteins were measured by their susceptibility to urea denaturation. Creation of a cavity the size of a -CH2-group destabilizes the enzyme by 1.1 kcal mol-1, and a cavity the size of three such groups by 4.0 kcal mol-1. Study holds ProTherm entries: 1959, 1960, 1961, 1962 Extra Details: dG and ddG were measured in the presence of 2.8M urea hydrophobic interactions; barnase; protein stability;,alpha-helices; beta-sheets; protein engineering

Submission Details

ID: RGFPFSiG

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:18 p.m.

Version: 1

Publication Details
Kellis JT;Nyberg K;Sali D;Fersht AR,Nature (1988) Contribution of hydrophobic interactions to protein stability. PMID:3386721
Additional Information

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