Update profile
    Change password
    Sign out

Our content has moved! Check out our protein biology page on lifetechnologies.com  Go now >

Lys-C Protease, MS Grade

Highly active alternative to trypsin that increases digestion efficiency.

Lys-C Protease, MS Grade

Thermo Scientific Lys-C Protease, MS Grade, is a highly purified native endoproteinase validated for maximum activity and stability in proteomic applications.

This Lys-C is a mass spectrometry (MS)-grade serine protease isolated from Lysobacter enzymogenes. Lys-C 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 can cleave lysines followed by prolines, making it ideal for sequential protein digestion followed by trypsin to decrease missed cleavages. These unique Lys-C 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 is commonly 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 (20µg).


  • 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
  • Versatile – effective enzyme activity under highly denaturing conditions (e.g., 8M urea)
  • C-terminal lysine cleavage specificity – at least 90% for a complex protein sample
  • Stable – provided in a lyophilized format


  • Improved sequence coverage of protein digests
  • De novo sequencing
  • Epigenetic studies
  • In-gel and in-solution digestion of proteins

Product Details:

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 remains active in highly denaturing conditions such as 8M urea, 2M 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.

A. Total ion chromatogram (TIC) of A549 cells digested with Thermo Scientific Lys-C Protease.
Total ion chromatogram of A549 cells digested with Thermo Scientific LysC Protease
B. Peptides identified after Lys-C digestion C. Proteins identified after Lys-C digestion
Comparison of peptides identified after digestion with Lys-C proteases. Comparison of proteins identified after digestion with Lys-C proteases.

Increased peptide identifications and reduced missed cleavages with Thermo Scientific Lys-C Protease, MS Grade. A) Total ion chromatogram (TIC) of A549 cell lysate digested with Thermo Scientific Lys-C. B) Number of peptides with no missed cleavages and peptides with one or two missed cleavages of an A549 cell lysate digested with three different Lys-C products (Thermo Scientific Lys-C, Part No. 90051; Promega rLys-C, #V1671; Roche Lys-C, #11420429001). C) Number of proteins identified. The A549 cell lysate sample (100µg) was prepared with the Thermo Scientific Pierce Mass Spec Sample Prep Kit for Cultured Cells and digested overnight in a 4M urea solution pH=8.0 with Lys-C at a 1:100 enzyme:protein ratio at 37°C. After C18 clean-up, the digested sample peptides (0.5µg) were separated using a Thermo Scientific EASY-Spray nanoflow PepMap RSLC C18 2μm 100Å 50cm x 75μm ID column coupled to a Thermo Scientific Orbitrap Fusion mass spectrometer. Data were searched on Sequest with a FDR of <1% using Thermo Scientific Proteome Discoverer 1.4.

General References:

  1. Simpson, Richard. (2003) Proteins and Proteomics, A Laboratory Manual, Cold Spring Harbor Press.

Related Products:

Pierce Trypsin Protease, MS Grade
Mass spectrometry reagents and kits
Detergent Removal Products
Mass Spec Sample Prep Kit for Cultured Cells

Ordering Information
Product # Description Pkg. Size Instructions MSDS CofA Price
90051 Lys-C Protease, MS Grade
Formulation: Lyophilized enzyme powder
Sufficient For: Lot-specific activity
1 x 20µg Product Instructions for product #90051 Lys-C Protease, MS Grade MSDS for product #90051 Lys-C Protease, MS Grade Certificate of Analysis for product #90051 Lys-C Protease, MS Grade $316.00

Now available on lifetechnologies.com

Instructions | MSDS | CofA
Product Instructions | MSDS | CofA  

Recommend this page

Follow Us
Email Sign-up  Email Announcements


Antibodies  |   Molecular Biology   |   Cell Biology   |  Thermo Scientific  |   * Trademarks  |   Privacy Statement
© 2015 Thermo Fisher Scientific Inc.   |   3747 N Meridian Rd, Rockford, IL USA 61101   |   1-800-874-3723  or  815-968-0747