Dear Dr. Pedro A Reche Gallardo, Our lab have developed a method to analyse protein-protein interface. You can download it from our ftp server mdl.ipc.pku.edu.cn/pub/software/PP_SITE . Though this program won't fit all your need, you can try it to get something useful. It is a free software just need you fill in a register form. Hope this will be helpful! Gao Ying Molecular Design Lab Institute of Physical Chemistry Peking University Beijing, P.R. China