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Proc Natl Acad Sci U S A. 1983 Jan; 80(2): 622–626.
PMCID: PMC393430

Calculation of volume fluctuation for globular protein models.


The extent of volume fluctuation is calculated for two simple geometrical models of globular protein molecules subjected to a potential that is proportional to the surface area freshly generated by the thermal breathing motion. The proportionality constant, gamma, has the unit of surface tension. The calculated values are compared with estimates made from the compressibility measurements. After an approximate correction for the hydration effect, the experimental values are found to be between those calculated by using gamma values of 25 and 46 cal/mol/A2 (1 cal = 4.184 J). These values bracket previously reported independent estimates of interfacial tension that presumably operates at the interface between a nonpolar molecule and water. This result appears to indicate that the solvent water plays a significant role in determining the extent of volume fluctuation of globular proteins and that the concept, and the actual value of the estimate, of the interfacial tension around a nonpolar molecule in water may, in fact, be useful in some applications.

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Selected References

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  • Finney JL, Gellatly BJ, Golton IC, Goodfellow J. Solvent effects and polar interactions in the structural stability and dynamics of globular proteins. Biophys J. 1980 Oct;32(1):17–33. [PMC free article] [PubMed]
  • Cooper A. Thermodynamic fluctuations in protein molecules. Proc Natl Acad Sci U S A. 1976 Aug;73(8):2740–2741. [PMC free article] [PubMed]
  • Eden D, Matthew JB, Rosa JJ, Richards FM. Increase in apparent compressibility of cytochrome c upon oxidation. Proc Natl Acad Sci U S A. 1982 Feb;79(3):815–819. [PMC free article] [PubMed]
  • Kuntz ID, Jr, Kauzmann W. Hydration of proteins and polypeptides. Adv Protein Chem. 1974;28:239–345. [PubMed]
  • Suezaki Y, Go N. Breathing mode of conformational fluctuations in globular proteins. Int J Pept Protein Res. 1975;7(4):333–334. [PubMed]
  • Levy RM, Perahia D, Karplus M. Molecular dynamics of an alpha-helical polypeptide: Temperature dependence and deviation from harmonic behavior. Proc Natl Acad Sci U S A. 1982 Feb;79(4):1346–1350. [PMC free article] [PubMed]
  • Lesk AM, Chothia C. Solvent accessibility, protein surfaces, and protein folding. Biophys J. 1980 Oct;32(1):35–47. [PMC free article] [PubMed]
  • Nozaki Y, Tanford C. The solubility of amino acids and two glycine peptides in aqueous ethanol and dioxane solutions. Establishment of a hydrophobicity scale. J Biol Chem. 1971 Apr 10;246(7):2211–2217. [PubMed]
  • Chothia C. Hydrophobic bonding and accessible surface area in proteins. Nature. 1974 Mar 22;248(446):338–339. [PubMed]
  • Lee B, Richards FM. The interpretation of protein structures: estimation of static accessibility. J Mol Biol. 1971 Feb 14;55(3):379–400. [PubMed]
  • Hermann RB. Use of solvent cavity area and number of packed solvent molecules around a solute in regard to hydrocarbon solubilities and hydrophobic interactions. Proc Natl Acad Sci U S A. 1977 Oct;74(10):4144–4145. [PMC free article] [PubMed]
  • Reynolds JA, Gilbert DB, Tanford C. Empirical correlation between hydrophobic free energy and aqueous cavity surface area. Proc Natl Acad Sci U S A. 1974 Aug;71(8):2925–2927. [PMC free article] [PubMed]

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