  A global optimization method called Greedy Neighborhood Search (GNS) and a
novel conformational sampling method using a spherical distribution is proposed
to find the minimum energy conformation of a protein-like heteropolymer model
called AB model. The AB model consists of hydrophobic (A) and hydrophilic (B)
monomers analogous to the real proteins. The AB model in three-dimensional
space is represented by simple bead-rod chain system which is identical to the
one-bead protein model. The minimum energy conformations of four different
sequences consisting of 13, 21, 34, and 55 monomers are obtained by the GNS
method. The minimum energies found are lower than those obtained by other
methods. Also the minimum energy conformations found have a similarity with the
real proteins forming a single hydrophobic core.
