Abstract
We enumerate the number of minimum energy compact structures (MECS) for a two dimensional heteropolymer model consisting of hydrophobic (H) and hydrophilic beads averaged over all possible sequences as a function of the total number of beads N and the number of H beads . The analysis of the average number of compact structures, which grows exponentially with N, gives no indication of logarithmic corrections to the free energy. For intermediate values of the ratio /N, we estimate that the average number of MECS—which has a minimum at /N=0.6±0.1—does not grow with N. Our results suggest that the late stages of protein folding should be restricted to the sampling of MECS only.
- Received 29 March 1993
DOI:https://doi.org/10.1103/PhysRevLett.71.2505
©1993 American Physical Society