Investigation of the stability and the helix-tail interaction of sCT and its various charged mutants based on comparative molecular dynamics simulations

Abstract

Salmon calcitonin (sCT) peptide has been widely used in the treatment of osteoporosis, Paget's disease and chronic pain. In this paper, we first tried to determine the best suitable force field based on the stability and helix properties of wild type sCT and we found that CHARMM27 is the most suitable one among the four different popular force fields tested. We secondly performed triple MD simulations of 300 ns at 310 K for each sCT mutant system. The simulation results indicated that the substitution of the Gln14 with Glu enable to formation of many additional salt bridges increasing stability. It was also observed that the substitution of the Gly10 with the Lys has enhanced helix-tail interaction. Consequently, we expect that our detailed simulation results can shed light on the future theoretical and experimental mutational studies of the sCT and help the development for its therapeutic purposes.