Thermo Scientific Asp-N Protease, MS Grade, is a highly specific endoproteinase used to improve sequence coverage in mass spectrometry protein identification applications.
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. 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 (2µg).
- 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
- Improved sequence coverage of protein digests
- In-solution digestion of proteins
- In-gel digestion of proteins
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 1M urea, 2M 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.
- Simpson, Richard. (2003) Proteins and Proteomics, A Laboratory Manual, Cold Spring Harbor Press.
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