Native endoproteinase Asp-N from Pseudomonas fragi. Designed for protein sequencing or sequence verification, analysis of protein structural domains, and cleavage of fusion proteins. Metalloprotease that specifically hydrolyses proteins at the N-terminal side of aspartic acid and cysteic acid residues. Inhibited by aprotinin, DFP, leupeptin, and TLCK. Suggested working concentration: 1:20 to 1:100 (protease:protein by weight) for sequence analysis.