Protein-protein interactions virtually regulate all processes inside cells, e.g. signal transduction, metabolic regulation, gene regulation, and immunological responses which occur in a specific way. Several experimental methods are capable of detecting interactions between proteins, which can range from cellular "resolution" to experiments which expose atom level interactions. However, the performance of these combined experiments which generate complete information regarding the network of protein interaction require great laboratorial effort in order to determine optimal empirical parameters for the production of the samples used in the measurements. Such a difficulty in the technical standpoint makes the in silico approach extremely useful, being able to guide experiments while reducing time and costs entailed by in vivo and/or in vitro studies. This study aims to determine physical-chemical characteristics which are essential to the aminoacids present in the formation of protein-protein interfaces that differentiate them from the residue present in active regions, in other words, that are not involved in the interactions.