Alpha-helix stability in proteins. II. Factors that influence stability at an internal position.


Abstract

The solvent-exposed residue Ala32 in the second alpha-helix of barnase was replaced by all other naturally occurring amino acids and the concomitant effects on the protein stability were determined. The results are assumed to reflect both the distinct conformational preferences of the different amino acids and also possible intrahelical interactions. The conformational preferences may be fully rationalized by invoking only a few physical principles. The results agree well with recently experimentally determined rank-order of helix-forming tendencies determined on a model peptide. There is very weak correlation between the results and the experimental host-guest values. There is a weak correlation between our results and the statistical helix propensities and a slightly better correlation with the positional-dependent statistical parameters of J. S. Richardson, and D. C. Richardson. Study holds ProTherm entries: 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189 Extra Details: dG_H2O values are calculated using m and Cm,dG and ddG were measured in the presence of [urea]50% protein stability; protein folding; alpha helix; barnase

Submission Details

ID: FjNiibiF4

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:14 p.m.

Version: 1

Publication Details
Horovitz A;Matthews JM;Fersht AR,J. Mol. Biol. (1992) Alpha-helix stability in proteins. II. Factors that influence stability at an internal position. PMID:1404369
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