Monte Carlo simulation study of melittin: protein folding and temperature dependence

The tetramerization of melittin, a 26-amino-acid peptide, is considered as a model for protein folding. The Monte Carlo simulation was used to study the folding arrangement of melittin, and the results are compared with the experiment. An acceptance rate of 50% for new configurations is achieved by using ranges of +/- 0.001 angstrom for the translations and +/- 15 degrees C for the rotations. Around 311 K, the folded structure of the protein has the greatest stability; the range from -40 to -80 shows the best. angles for melittin. The final optimized structure of melittin strongly depends on the temperature. The melittin tetramer is found to have a temperature of maximum stability ranging from 35.5 to 43 degrees C.