A Novel Cell-Penetrating Peptide Derived from Human Eosinophil Cationic Protein
BACKGROUND Eosinophil cationic protein (ECP) and eosinophil derived-neurotoxin (EDN) are homologous ribonuclease (RNAse) A family proteins. The objective of the present study was to in silico characterize ECP and EDN with respect to their cytotoxic activities. MATERIALS AND METHODS Structural, physicochemical, and conserved domain characterizations were carried-out using open-source software, such as InterProScan, NetOGlyc, NetPhos and Discovery Studio 3.1. RESULTS The proteins did not have atypical conserved domains. EDN had a greater number of glutamine amino acid residues, whereas ECP had a predominance of arginine. ECP had four possible N-glycosylation, three O-glycosylation and four phosphorylation sites. EDN had five putative N-glycosylation, three phosphorylation and no O-glycosylation sites. CONCLUSION The greater cationicity of ECP may be related to its higher cytotoxicity and to the fact that the varying post-translational modification profiles can generate functional differences from structural alteration. In vivo and in vitro studies need to be performed in order to confirm these predictions.