Merck, 11418025001, Trypsin Sequencing Grade, modified

General description
Trypsin Sequencing Grade, modified, is isolated from bovine pancreas as a highly purified and specific protease, and subsequently modified.

Trypsin is a highly efficient and specific protease widely used in proteomics for protein digestion. It produces short peptides with specific characteristics that are compatible with current separation and identification methods such as liquid chromatography, mass spectrometry (MS).

Inhibitors: TLCK, DFP, PMSF, leupeptin, soybean trypsin inhibitor, trypsin inhibitor from hen egg, aprotinin, α2-macroglobulin,α1-antitrypsin, APMSF, and antipain.
Application
Use Trypsin Sequencing Grade, modified, to generate glycopeptides from purified glycoproteins.
It is used for:Protein-structure elucidation
Tryptic mapping
Fingerprinting analysis
Sequence analysis
Translocation studies
Protein identification
Protein digestion during lipoprotein preparation for liquid chromatography-tandem mass spectrometry (LC-MS/MS)

Biochem/physiol Actions
Trypsin is a serine endopeptidase. At pH 7.5–9, it specifically hydrolyzes proteins and peptide bonds C-terminally of Iysine and arginine. Amide and ester bonds of Arg and Lys are also cleaved. The specificity of Trypsin Sequencing Grade, modified, is verified with the oxidized B-chain of insulin (insulin Box) as a substrate. High concentrations of Trypsin Sequencing Grade, modified, one part by weight enzyme with 9 parts by weight insulin Box, are incubated for 18 hours to detect traces ofchymotrypsin impurities.
Preparation Note
Working concentration: 1/100 to 1/5 of the protein by weight
Storage conditions (working solution): -15 to -25 °C
Trypsin Sequencing Grade, modified, is more resistant to autolysis, even at pH values in the neutral and weakly basic range. The enzyme can be used in high concentrations.
A solution in 1% acetic acid or 1 mM HCI can be used for up to one week when stored at 2 to 8° C. Stored in aliquots at -15 to -25 °C, the solution is stable for at least one year without loss of activity.
Store dry
Analysis Note
Purity: Free of impurities that may interfere with the separation of peptides in reversed-phase HPLC.
Other Notes
For life science research only. Not for use in diagnostic procedures.