Solvent effects and polar interactions in the structural stability and dynamics of globular proteins

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(80)84913-7· OSTI ID:6857211

Finney, J L; Gellatly, B J; Golton, I C; Goodfellow, J

Using detailed hydrogen bonding, surface exposure, internal environment, and solvent interaction calculations on several proteins, in conjnction with data from quantum mechanical hydrogen-bonding studies, various contributions to the free energy of folding are estimated and their likely relative significance discussed. A picture emerges of globular proteins as extremely well-fitting jigsaw-puzzles, in which no single driving force dominates the marginal stability of the native conformation. Rather, the folded structure is seen as the result of a complex global maximization of several strongly-interacting driving forces. In particular, the necessity to maintain very efficient internal hydrogen-bonding, and the role of the solvent as a hydrogen-bond sink, are stressed as strong constraints on the (incomplete) maximization of hydrophobic effects. The possible significance of internal dipole-induced dipole interactions is discussed tentatively. Although quantitative estimates of the various contributions remain uncertain, consideration of effective force constants suggests that polar, including solvent, interactions may largely determine the overall curvatures of the native conformation's potential well, and be important in controlling the flexibility of local regions which are important for the exact positioning of groups during enzyme catalysis, as well as the molecule's overall dynamics. In contrast, hydrophobic interactions change less for small geometrical perturbations, and seem more relevant to directing the folding protein along a path to a region in configurational space where the polar interactions can switch on for the final docking.

• Research Organization: Univ. of London, England
• OSTI ID: 6857211
• Journal Information: Biophys. J.; (United States), Vol. 32:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PROTEINS
STRUCTURAL CHEMICAL ANALYSIS
SOLVENT PROPERTIES
CONFIGURATION INTERACTION
BIOCHEMICAL REACTION KINETICS
BIOPHYSICS
DIPOLES
FREE ENTHALPY
MOLECULAR BIOLOGY
MOLECULAR STRUCTURE
SPATIAL DEPENDENCE
ENERGY
KINETICS
MULTIPOLES
ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
THERMODYNAMIC PROPERTIES
550200* - Biochemistry