Statistical mechanics of the two-dimensional hydrogen-bonding self-avoiding walk including solvent effects.

A two-dimensional square-lattice model for the formation of secondary structures in proteins, the hydrogen-bonding model, is extended to include the effects of solvent quality. This is achieved by allowing configuration-dependent nearest-neighbor interactions. The phase diagram is presented and found to have a much richer variety of phases than either the pure hydrogen-bonding self-avoiding walk model or the standard Theta-point model.