Free energy of burying hydrophobic residues in the interface between protein subunits.

Content Provider	Semantic Scholar
Author	Vallone, Beatrice Miele, Adriana Erica Vecchini, Paola Chiancone, Emilia Brunori, Maurizio
Copyright Year	1998
Abstract	We have obtained an experimental estimate of the free energy change associated with variations at the interface between protein subunits, a subject that has raised considerable interest since the concept of accessible surface area was introduced by Lee and Richards [Lee, B. & Richards, F. M. (1971) J. Mol. Biol. 55, 379-400]. We determined by analytical ultracentrifugation the dimer-tetramer equilibrium constant of five single and three double mutants of human Hb. One mutation is at the stationary alpha1 beta1 interface, and all of the others are at the sliding alpha1 beta2 interface where cleavage of the tetramer into dimers and ligand-linked allosteric changes are known to occur. A surprisingly good linear correlation between the change in the free energy of association of the mutants and the change in buried hydrophobic surface area was obtained, after corrections for the energetic cost of losing steric complementarity at the alphabeta dimer interface. The slope yields an interface stabilization free energy of -15 +/- 1.2 cal/mol upon burial of 1 A2 of hydrophobic surface, in very good agreement with the theoretical estimate given by Eisenberg and McLachlan [Eisenberg, D. & McLachlan, A. D. (1986) Nature (London) 319, 199-203].
File Format	PDF HTM / HTML
DOI	10.1073/pnas.95.11.6103
Alternate Webpage(s)	http://www.pnas.org/content/95/11/6103.full.pdf
PubMed reference number	9600924
Alternate Webpage(s)	https://doi.org/10.1073/pnas.95.11.6103
Journal	Medline
Volume Number	95
Issue Number	11
Journal	Proceedings of the National Academy of Sciences of the United States of America
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article