Protease S. aureus V8 (Endoproteinase-Glu-C) specifically cleaves peptide bonds on the COOH-terminal side of either aspartic or glutamic acids. In the presence of ammonium, the enzyme specificity is limited to glutamic sites. It has a molecular weight of 27,000 daltons and optimum pH's of 4.0 and 7.8 with hemoglobin as the substrate