Among several approximate methods investigated, the AMOEBApro13 polarizable force field showed the best compromise between cost and accuracy. Tested on three systems that are the cis-, trans-proline protonated GPGG and the doubly-protonated gramicidin S decapeptide, the approach was successful in identifying B3LYP DFT GM within maximum 2 kcal/mol from the putative surrogate GM. The GAFF force field also succeeded for GPGG isomers but failed for gramicidin due to a large offset in the energy predictions. As opposed to the more cumbersome and expensive ab initio simulated annealing employed in earlier studies, GPGG local minima were generated over 10 serial GA runs in less than 3 hours on a single workstation, and only 7 hours were necessary for the larger gramicidin system. Obviously, these timings can be further improved by parallelizing between multiple GA instances.