Components
Trypsin consists of a single chain polypeptide of 223 amino acid residues, produced by the removal of the N-terminal hexapeptide from trypsinogen which is cleaved at the Lys - lle peptide bond. The sequence of amino acids is cross-linked by 6 disulfide bridges. This is the native form of trypsin, beta-trypsin. BETA-trypsin can be autolyzed, cleaving at the Lys - Ser residue, to produce alpha-trypsin. Trypsin is a member of the serine protease family.
Caution
Solutions in 1 mM HCl are stable for 1 year in aliquots and stored at -20°C. The presence of Ca2+ will also diminish the self-autolysis of trypsin and maintain its stability in solution. Trypsin will also retain most of its activity in 2.0 M urea, 2.0 M guanidine HCl, or 0.1% (w/v) SDS.
Preparation Note
Solubilizing trypsin should be done with a buffered salt solution containing no Ca2+ or Mg2+. This product is from pancreas sourced from New Zealand. It is soluble in 1 mM HCl at 1 mg/mL.
Unit Definition
1 BTEE 單位 = 320 ATEE 單位
Application
For trypsin digestion of peptides, use a ratio of about 1:100 to 1:20 for trypsin:peptide. The typical use for this product is in removing adherent cells from a culture surface. The concentration of trypsin necessary to dislodge cells from their substrate is dependent primarily on the cell type and the age of the culture. Trypsins have also been used for the re-suspension of cells during cell culture, in proteomics research for digestion of proteins and in various in-gel digestions. Additional applications include assessing crystallization by membrane-based techniques and in a study to determine that protein folding rates and yields can be limited by the presence of kinetic traps.
Biochem/physiol Actions
Trypsin cleaves peptides on the C-terminal side of lysine and arginine residues. The rate of hydrolysis of this reaction is slowed if an acidic residue is on either side of the cleavage site and hydrolysis is stopped if a proline residue is on the carboxyl side of the cleavage site. The optimal pH for trypsin activity is 7-9. Trypsin can also act to cleave ester and amide linkages of synthetic derivatives of amino acids. EDTA is added to trypsin solutions as a chelating agent that neutralizes calcium and magnesium ions that obscure the peptide bonds on which trypsin acts. Removing these ions increases the enzymatic activity. Serine protease inhibitors, including DFP, TLCK, APMSF, AEBSEF, and aprotinin, amongst others, will inhibit Trypsin.
Cell Dissociation and Cell Lysis, Core Bioreagents,Core Bioreagents Enzymes, Enzyme Class Index,Proteases, Proteases & Protein Sequencing,Proteolytic Enzymes, Proteolytic Enzymes and Substrates, Research Essentials, Selective Proteolytic Enzymes, Trypsin, Trypsin for General Research Applications, 生化試劑, 酶、抑制劑和底物