MONTE-CARLO METHODS FOR SHORT POLYPEPTIDES

Nonphysical sampling Monte Carlo techniques that enable average struct ural properties of short in vacuo polypeptide chains to be calculated accurately are discussed. Updating algorithms developed for Monte Carl o studies of flexible polymer chains are modified and adapted for poly peptide chain systems to improve conformational sampling. Utilizing th ese methods, the effect of bond angle and bond length constraints in M onte Carlo simulations are examined and it is demonstrated that angle constraints bias structural averages without greatly reducing the comp utational work. (C) 1998 American lnstitute of Physics. [S0021-9606(98 )50244-9].