Purification and some properties of lysostaphin, a glycylglycine endopeptidase from the culture liquid of Staphylococcus simulans biovar staphylolyticus.

This work presents a method for purification of lysostaphin, a glycylglycine endopeptidase, from the culture liquid of S. simulans biovar staphylolyticus to homogeneity in a few steps. The method includes ultrafiltration and ion-exchange and hydrophobic chromatographies.

Use of trinitrophenylation for quantification of protease and peptidase activities.

A sensitive and precise method for quantifying protease and peptidase activities is suggested. N-Terminal amino groups of peptides which are formed during hydrolysis of the substrates react with trinitrobenzenesulfonic acid (TNBS), and the trinitrophenyl (TNP) derivatives are determined spectrophotometrically. Spontaneous hydrolysis of TNBS is considerably diminished on trinitrophenylation at pH 7.