ABSTRACT
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.
Subject(s)
Eosinophil Cationic Protein/metabolism , Eosinophil-Derived Neurotoxin/metabolism , Gene Expression Regulation , Arginine/chemistry , Computational Biology , Databases, Protein , Glutamine/chemistry , Glycosylation , Humans , Protein Processing, Post-Translational , Protein Structure, Secondary , Protein Structure, Tertiary , Ribonuclease, Pancreatic/chemistry , SoftwareABSTRACT
The eosinophil cationic protein (ECP) is a small polypeptide that originates from activated eosinophil granulocytes. A wide range of stimuli has been shown to induce the secretion of ECP. The gene that encodes the human ECP is located on chromosome 14, and the protein shares the overall three-dimensional structure and the RNase active-site residues with other proteins in the RNase A superfamily. Several single-nucleotide polymorphisms in the human ECP gene have been currently described. ECP has many biological functions, including an immunoregulatory function, the regulation of fibroblast activity, and the induction of mucus secretion in the airway. Additionally, the protein is a potent cytotoxic molecule and has the capacity to kill mammalian and nonmammalian cells. The purpose of this article was to review the known biological and genetic characteristics of ECP that contribute to the understanding of this protein's role in the development and progression of a wide variety of diseases.
