Endoproteinase Asp-N is a metalloprotease that hydrolyzes peptide bonds on the amino terminus of aspartic and cysteic acid(oxidized cysteine). If the cysteine residue is reduced or alkylated,Endoproteinase Asp-Nwill cleave only the amino terminus ofaspartic acidresidues. The enzyme is supplied with a 250 mM sodium phosphate buffer (pH 8.0).