B. Fain et al., Determination of optimal Chebyshev-expanded hydrophobic discrimination function for globular proteins, IBM J RES, 45(3-4), 2001, pp. 525-532
We describe the development of a scoring function designed to model the hyd
rophobic effect in protein folding. An optimization technique is used to de
termine the best functional form of the hydrophobic potential. The scoring
function is expanded using the Chebyshev polynomials, for which the coeffic
ients are determined by minimizing the Z-score of native structures in the
ensembles of alternate conformations. (The Z-score is the score relative to
the mean, measured in units of standard deviation.) The derived effective
potential is tested on decoy sets conventionally used in such studies. The
function is able to discriminate very well between correct and incorrect fo
lds, despite the fact that it simply counts the number of neighbors of each
amino acid. Our results show that the techniques of Z-score optimization a
nd Chebyshev expansion work, and work well. Our results also confirm that h
ydrophobic effect is one of the principal driving forces in protein folding
.