where ∆G GB,AB , ∆G GB,A , and ∆G GB,B are the solvation energy of binary complex AB as well as proteins A and B evaluated using MMPB/SA with the ensemble obtained in the ternary simulation, respectively. The cooperative solvation free energy was calculated via, ∆G desolv,AB ALB = ∆G GB,ALB -∆G GB,AL -∆G GB,BL -∆G GB,AB +∆G GB,A +∆G GB,B +∆G GB,L ALB .