Trypsin, Sequencing Grade

Trypsin, Sequencing Grade specifically hydrolyzes peptide bonds at the carboxylic sides of lysine and arginine residues. Unmodified trypsin is subject to autolysis, generating fragments that can interfere with mass spectrometry analysis of the peptides. Promega Trypsin has been modified by reductive methylation, rendering it extremely resistant to autolytic digestion.

Trypsin Gold

Trypsin Gold, Mass Spectrometry Grade, has extremely high specific activity. Modified trypsin is maximally active in the range of pH 7.0-9.0 and is reversibly inactivated at pH <4.0. It is resistant to mild denaturing conditions such as 0.1% SDS, 1M urea or 10% acetonitrile and retains 5% of its activity in 2M guanidine HCl.

ProteaseMAX™ Surfactant

ProteaseMAX™ Surfactant is a high-quality reagent for use in protein and peptide sample preparation. ProteaseMAX™ Surfactant solubilizes proteins and ensures fast and improved protein digestion. It is designed to degrade over the course of a digestion reaction. For in-gel protein digestions, ProteaseMAX™ Surfactant also improves the recovery of peptides.

Immobilized Trypsin

Immobilized Trypsin provides a fast and convenient method for digesting purified or complex proteins over a wide range of concentrations. With the spin column format, digested peptides are easily separated from the immobilized trypsin, reducing enzyme interference during analysis.

Sequence Specific Proteases

Chymotrypsin is a highly-purified serine endopeptidase derived from bovine pancreas that preferentially hydrolyzes at the carboxyl side of aromatic amino acids: Tyr, Phe and Trp. Cleavage may also be observed, but at a lower rate, at Leu and Met.

Endoproteinase Lys-C is a sequencing grade serine protease isolated from Lysobacter enzymogenes as a highly purified protease that hydrolyses specifically at the carboxyl side of Lys.

Recombinant Lys-C, Mass Spec Grade is a recombinant Lys-C expressed in E. coli. Sequence origin of rLys-C is Protease IV from Pseudomonas aeruginosa. Similar to a native Lys-C, rLys-C cleaves at the carboxyl side of lysine residues with exceptional specificity. rLys-C retains proteolytic activity under protein denaturing conditions such as 8M urea, which is used to improve digestion of proteolytically resistant proteins.

Asp-N, Sequencing Grade is an endoproteinase that hydrolyzes peptide bonds on the N-terminal side of aspartic and cysteic acid residues: Asp and Cys. Asp-N activity is optimal in the pH range of 4.0—9.0. This sequencing grade enzyme can be used alone or in combination with other proteases to produce protein digests for peptide mapping applications or protein identification by peptide mass fingerprinting or MS/MS spectral matching.

Glu-C, Sequencing Grade (S. aureus V8), is a serine protease that specifically cleaves at the C-terminus of either aspartic or glutamic acid residues. In ammonium bicarbonate and ammonium acetate the enzyme specificity is higher at the glutamic residues. In phosphate buffers cleavage occurs at the aspartic and glutamic residues. Glu-C activity is optimal in the pH range of 4.0—9.0. This sequencing grade enzyme can be used alone or in combination with other proteases to produce protein digests for peptide mapping applications or protein identification by peptide mass fingerprinting or MS/MS spectral matching.

Arg-C (clostripain), Sequencing Grade is an endopeptidase that cleaves at the C-terminus of arginine residues, including the sites next to proline. Cleavage also will occur at lysine residues. This sequencing grade enzyme can be used alone or in combination with other proteases for protein analysis by mass spectrometry and other applications. Arg-C activity is optimal in the pH range of 7.6—7.9.

Elastase is a serine protease that preferentially cleaves at the C-terminus of alanine, valine, serine, glycine, leucine or isoleucine. Elastase has a unique capability of digesting elastin. This enzyme can be used alone or in combination with other proteases for protein analysis by mass spectrometry and other applications. Elastase activity is optimal at pH 9.0.

Pepsin preferentially cleaves at the C-terminus of phenylalanine, leucine, tyrosine and tryptophan. This protease can be used alone or in combination with other proteases for protein analysis by mass spectrometry and other applications. Pepsin activity is optimal at pH 1.0—3.0.

Thermolysin is a thermostable metalloproteinase. The 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. The optimal digestion temperature range is 65–85°C. Thermolysin activity is optimal at pH 5.0—8.5.

Other Proteases

Endoglycosidase H (Endo H) is a recombinant glycosidase cloned from Streptomyces plicatus and overexpressed in E. coli. Endo H cleaves the chitobiose core of high mannose and a limited number of hybrid oligosaccharides from N-linked glycoproteins.

Protein Deglycosylation Mix is a mixture of five protein deglycosidases (PNGase F, O-Glycosidase, Neuraminidase, β1-4 Galactosidase, β-N-Acetylglucosaminidase) capable of removing glycans from both O-linked and N-linked glycosylation sites.

Fetuin is a glycoprotein with O-linked and N-linked glycosylation sites.