Abstract
Monte Carlo simulations of a small protein, carmbin, were carried out with and without hydration energy. The methodology presented here is characterized, as compared with the other similar simulations of proteins in solution, by two points: (1) protein conformations are treated in fixed geometry so that dihedral angles are independent variables rather than cartesian coordinates of atoms; and (2) instead of treating water molecules explicitly in the calculation, hydration energy is incorporated in the conformational energy function in the form of Σg i A i, whereA i is the accessible surface area of an atomic groupi in a given conformation, andg i is the free energy of hydration per unit surface area of the atomic group (i.e., hydration-shell model). Reality of this model was tested by carrying out Monte Carlo simulations for the two kinds of starting conformations, native and unfolded ones, and in the two kinds of systems,in vacuo and solution. In the simulations starting from the native conformation, the differences between the mean propertiesin vacuo and solution simulations are not very large, but their fluctuations around the mean conformation during the simulation are relatively smaller in solution thanin vacuo. On the other hand, in the simulations starting from the unfolded conformation, the molecule fluctuates much more largely in solution thanin vacuo, and the effects of taking into account the hydration energy are pronounced very much. The results suggest that the method presented in this paper is useful for the simulations of proteins in solution.
Similar content being viewed by others
References
Abe, H., Braun, W., Noguti, T., and Go, N. (1984).Comp. Chem. 8, 239–247.
Brunger, A. T., Brooks, C. L., and Karplus, M. (1985).Proc. Natl. Acad. Sci. USA 82, 8458–8463.
Hendrickson, W. A., and Teeter, M. M. (1981).Nature 290, 107–113.
Hermans, J., Berendsen, H. J. C., van Gunsteren, W. F., and Postma, J. P. M. (1984).Biopolymers 23, 1513–1518.
Hodes, Z. I., Nemethy, G., and Scheraga, H. A. (1979).Biopolymers 18, 1565–1610.
Karplus, M. (1987).Physics Today 40, 68–72.
Kruger, P., Strassburger, W., Wollmer, A., and van Gunsteren, W. F. (1985).Eur. Biophys. J. 13, 77–88.
Levitt, M., and Sharon, R. (1988).Proc. Natl. Acad. Sci. USA 85, 7557–7561.
Momany, F. A., McGuire, R. F., Burgess, A. W., and Scheraga, H. A. (1975).J. Phys. Chem. 79, 2361–2381.
Noguti, T., and Go, N. (1983).J. Phys. Soc. Jpn 52, 3685–3690.
Noguti, T., and Go, N. (1985).Biopolymers 24, 527–546.
Ooi, T., and Oobatake, T. (1988).J. Biochem. 103, 114–120.
Ooi, T., Oobatake, M., Nemethy, G., and Scheraga, H. A. (1987).Proc. Natl. Acad. Sci. USA 84, 3086–3090.
Paterson, Y., Nemethy, G., and Scheraga, H. A. (1981).Ann. N.Y. Acad. Sci. 367, 132–149.
Richmond, T. J. (1984).J. Mol. Biol. 178, 63–89.
Teeter, M. M. (1984).Proc Natl. Acad. Sci. USA 81, 6014–6018.
van Gunsteren, W. F., Berendsen, H. J. C., Hermans, J., Hol, W. G. J., and Postma, J. P. M. (1983).Proc. Natl. Acad. Sci. USA 80, 4315–4319.
van Gunsteren, W. F., and Karplus, M. (1982).Biochemistry 21, 2259–2274.
Wako, H., and Go, N. (1987).J. Comp. Chem. 8, 625–635.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wako, H. Monte Carlo simulations of a protein molecule with and without hydration energy calculated by the hydration-shell model. J Protein Chem 8, 733–747 (1989). https://doi.org/10.1007/BF01024898
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01024898