Promega Corporation announced that it has added four new proteases to its range of protein sample prep reagents: pepsin, elastase, sequencing grade clostripain, and thermolysin. These proteases are the latest addition to Promega’s range of protein sample prep reagents, which includes Trypsin Gold.
The proteases are provided in a lyophilized format, enabling resuspension in any buffer. Applications include use in peptide mapping and protein identification experiments, and in characterization of post-translational modifications.
Pepsin preferentially cleaves at the C-terminus of phenylalanine, leucine, tyrosine and tryptophan. Elastase is a serine protease that has a unique capability of digesting elastin, preferentially cleaving at the C-terminus of alanine, valine, serine, glycine, leucine or isoleucine. Arg-C (clostripain) is a sequencing grade endopeptidase that cleaves at the C-terminus of arginine residues, including sites next to proline. Cleavage also will occur at lysine residues. These three enzymes may be used alone or in combination with other proteases for protein analysis by mass spectrometry and other applications.
Thermolysin is a thermostable metalloproteinase with optimal digestion temperature range of 65–85°C. High digestion temperatures may be used as an alternative to denaturants to improve digestion of proteolytically resistant proteins. Thermolysin preferentially cleaves at the N-terminus of the hydrophobic residues leucine, phenylalanine, valine, isoleucine, alanine and methionine.