Recombinant Lys-C, Mass Spec Grade

• Cat.No.: Lys-C-38

Specification

• Description: rLys-C, Mass Spec Grade, specifically hydrolyzes peptide bonds at the carboxyl side of lysine residues. 8 M urea solution is recommended for denaturation. rLys-C can efficiently cleave difficult-to-digest proteins because rLys-C remains its activity under denaturation conditions.
• Form: Lyophilized powder
• Bio-activity: 25 units/min/mg
• Molecular Mass: 27 kDa
• Purity: > 99.9 % rLys-C peak area analyzed by HPLC at 280nm.
• Storage: Store the lyophilized powder at -20 centigrade, store reconstituted enzyme at -80 centigrade.
• CAS No.: 78642-25-8
• Shelf life: 24 months at -20 centigrade
• Stability: rLys-C is maximally active in the pH 8 and reversibly inactivated at pH 3.
• Usage Notes: Standard In-Solution Protein Digestion: 1. For maximum activity, resuspend Mass Spectrum Grade rLys-C in resuspension buffer provided. 2. Recommend using 6-8 M urea and 50 mM Tris-HCl (pH 8) to denature protein or protein mixture prior to digestion. 3. Add rLys-C to the mixture to reach a protein: protease ratio of 25: 1 (w/w). Mix well and incubate at 37 centigrade for 3-4 hours.
• Specificity: < 5 % nonspecific cleavage of Escherichia Coli digests with incubation at 37 centigrade for 4 h, analyzed by LC-MS/MS.
• Unit Definition: One unit is the amount of Mass spectrum Grade rLys-C will hydrolyze 1.0 umol of N-p-Tosyl-Gly-Pro-Lysp-Nitroanilide per minute at pH7.7 at 25 centigrade, A405, Light path=1cm.
• LC-MS/MS Analysis: Human Serum Albumin (HSA) was dissolved, denatured at 37 centigrade for 1 h, diluted at pH 8.0, and incubated with rLys-C for 4 h. The digest was analyzed by LC-MS/MS, and peptide results matched the peptides generated in a theoretical digests of HSA by rLys-C.
• Resuspension Buffer: rLys C Resuspension Buffer is composed of 50 mM Acetic acid buffer.
• MALDI-TOF Analysis: rLys-C is analyzed by MALDI-TOF, impurity peak is not found.