#Id: 8459
#Unit 1. Molecules and their Interaction Relevant to Biology
Five types of constraints affect the stability of an helix:
(1) the intrinsic propensity of an amino acid residue to form an helix;
(2) the interactions between R groups, particularly those spaced three (or four) residues apart;
(3) the bulkiness of adjacent R groups;
(4) the occurrence of Pro and Gly residues; and
(5) interactions between amino acid residues at the ends of the helical segment and the electric dipole inherent to the helix.
