Estimates of the loss of main-chain conformational entropy of different residues on protein folding

The average contribution of conformational entropy for individual amino aci d residues towards the free energy of protein folding is not well understoo d. We have developed empirical scales for the loss of the main-chain (torsi on angles, phi and psi) conformational entropy by taking its side-chain int o account. The analysis shows that the main-chain component of the total co nformational entropy loss for a residue is significant and reflects intrins ic characteristics associated with individual residues. The values have dir ect correlation with the hydrophobicity values and this has important beari ng on the folding process. (C) 1999 Wiley-Liss, Inc.