Thermo Scientific™ Pierce™ Lys-C Protease, MS Grade is a highly purified native endoproteinase validated for maximum activity and stability in proteomic applications.
Features of Lys-C Protease, MS Grade include:
• Enhanced digestion—use in tandem with trypsin to decrease tryptic missed cleavages
• Increased sequence coverage—better protein characterization results from overlapping peptides with complementary chromatographic, ionization, and fragmentation properties
• Versatility—effective enzyme activity under highly denaturing conditions (e.g., 8 M urea)
• C-terminal lysine cleavage specificity—at least 90% for a complex protein sample
• Stability—provided in a lyophilized format
This is a mass spectrometry (MS)-grade serine protease isolated from Lysobacter enzymogenes. Lys-C protease has high activity and specificity for lysine residues, resulting in larger peptides and less sample complexity than trypsin (i.e., fewer peptides). Unlike trypsin, Lys-C protease can cleave lysines followed by prolines, making it ideal for sequential protein digestion followed by trypsin to decrease missed cleavages. These unique Lys-C protease properties ensure high digestion efficiency when used alone or followed by tryptic digestion. Additionally, Lys-C prototypic peptides typically have higher charge states, making it an enzyme of choice for use with ETD fragmentation.
Lys-C protease is commonly used in phosphopeptide enrichment workflows because it generates peptides with primary amines at both the N- and C-terminus, allowing the fragments to be double-labeled with amine-reactive isobaric tags. This results in enhanced peptide ionization and improved limits of quantitation since more fragment ions can be re-isolated during MS3 acquisition. This enzyme can be used for in-solution or in-gel digestion workflows to produce peptides for LC-MS/MS protein identification. This Lys-C enzyme is packaged lyophilized (20 µg or 100 µg quantities).
The endoproteinase Lys-C specifically hydrolyzes proteins at the carboxyl side of lysine. Efficient protein digestion can be completed in 2 hours at 37°C. Lys-C protease remains active in highly denaturing conditions such as 8 M urea, 2 M guanidine-HCl, 1% SDS, 2% CHAPS, and 40% acetonitrile and functions well within pH 7–9 (maximal activity at pH 8). This lyophilized enzyme has a mass of 30 kDa and is stable for 1 year when stored at –20°C.
• Improved sequence coverage of protein digests
• De novo sequencing
• Epigenetic studies
• In-gel and in-solution digestion of proteins