Asp-N Protease, MS Grade, is a highly specific endoproteinase used to improve sequence coverage in mass spectrometry protein identification applications. Store at -20˚C in a nonfrost-free freezer.

• Complementary to tryptic digests – hydrolyzes proteins specifically at the amino side of aspartate and cysteic acid residues
• Increased sequence coverage – better protein characterization results from overlapping peptides with complementary chromatographic, ionization and fragmentation properties
• High specific activity – greater than 20,000 units/mg protein
• N-terminal arginine cleavage specificity – at least 90% for a complex protein sample
• Stable – provided in a lyophilized format

This Asp-N is a mass spectrometry (MS)-grade zinc metalloproteinase derived from a mutant strain of Pseudomonas fragi and requires a trace amount of zinc for activity

The endoproteinase AspN cleaves primarily at amino side of aspartate residues and cysteic acid residues that result from the oxidization of cysteine residues, generating a limited number of peptide fragments. Cleavage can also occur at glutamic residues; however, the rate of cleavage at the glutamyl residues is significantly lower than the rate of cleavage at the aspartic acid residues. AspN can efficiently digest protein in 2 - 20 hours at 37˚C. AspN remains active under denaturing conditions such as 1 M urea, 2 M guanidine∙HCl, 0.1% SDS, 2% CHAPS and 10% acetonitrile with optimal activity in the pH range of 6 - 8. This lyophilized enzyme has a mass of 27 kDa and is stable for 1 year when stored at -20˚C.

Asp-N can be used alone or in parallel with trypsin or other proteases to produce protein digests for peptide mapping and protein sequencing. Asp-N protease is suitable for either in-solution or in-gel digestion workflows. This Asp-N enzyme is packaged lyophilized (2 µg).