How do thermophilic proteins deal with heat?

Citation
S. Kumar et R. Nussinov, How do thermophilic proteins deal with heat?, CELL MOL L, 58(9), 2001, pp. 1216-1233
Citations number
122
Language
INGLESE
art.tipo
Review
Categorie Soggetti
Cell & Developmental Biology
Journal title
CELLULAR AND MOLECULAR LIFE SCIENCES
ISSN journal
1420-682X → ACNP
Volume
58
Issue
9
Year of publication
2001
Pages
1216 - 1233
Database
ISI
SICI code
1420-682X(200108)58:9<1216:HDTPDW>2.0.ZU;2-9
Abstract
Recent years have witnessed an explosion of sequence and structural informa tion for proteins from hyperthermophilic and thermophilic organisms. Comple te genome sequences are available for many hyperthermophilic archaeons. Her e, we review some recent studies on protein thermostability along with work from our laboratory. A large number of sequence and structural factors are thought to contribute toward higher intrinsic thermal stability of protein s from these organisms. The most consistent are surface loop deletion, incr eased occurrence of hydrophobic residues with branched side chains and an i ncreased proportion of charged residues at the expense of uncharged polar r esidues. The energetic contribution of electrostatic interactions such as s alt bridges and their networks toward protein stability can be stabilizing or destabilizing. For hyperthermophilic proteins, the contribution is mostl y stabilizing. Macroscopically, improvement in electrostatic interactions a nd strengthening of hydrophobic cores by branched apolar residues increase the enthalpy change between the folded and unfolded states of a thermophili c protein. At the same time, surface loop deletion contributes to decreased conformational entropy and decreased heat capacity change between the fold ed and unfolded states of the protein.