Before revision:  We calculate the potential of mean force between poly(lysine) and poly(glutamate) oligomers using three different forcfields , an atomistic forcefield and two coarse-grained forcefields .
After revision:  We calculate the potential of mean force between poly(lysine) and poly(glutamate) oligomers using three different forcfields , an atomistic force field and two coarse-grained forcefields .