Position-dependent protein mutant profile based on mean force field calculation

The application of the mean force field in protein mutant stabilityprediction is explored. Based on protein main chain characteristics,including polar fraction, accessibility and dihedral angles,the mean force field was constructed to evaluate the compatibilitybetween an amino acid residue and its environment, from whicha position-dependent protein mutant profile was constructed.At each position along a protein sequence, the native residuewas replaced by the other 19 types of amino acid residues. Thematches were evaluated by energies from mean force field calculation,from which a mutant profile along the protein sequence was derived.General characteristics of such a profile were analyzed. Mutantstabilities for two sets of mutants in two proteins were foundto be reasonable compared with experimental data, which indicatesthat the present method can act as a guide in protein engineeringand as an effective scoring matrix in protein sequence–structurealignment studies.