Description_x000D_ General description_x000D_ Thermolysin is a protease that has specificity different from other proteases available for sequence investigations._x000D_ Application_x000D_ Non-specific Protease Activity Assay Video_x000D_ A thermostable (thermophilic) extracellular metalloendopeptidase containing four calcium ions. Cofactors are zinc and calcium. Hydrolyzes protein bonds on the N-terminal side of hydrophobic amino acid residues. The pH optimum is 8.0 and the optimal temperature for activity is 70 °C. Considerably stable from pH 5 to 9.5. Thermolysin has a low cleavage specificity, therefore, it produces a number of short fragments that are suitable for sequencing. Preferential cleavage: X-cleavage-Y-Z where X=any amino acid; Y=Leu, Phe, Ile, Val, Met, Ala and Z is any amino acid other than Pro. Cleavage N-terminal to Leu is preferred over cleavage of N-terminal to Phe which is preferred over the others. Often used to do limited proteolysis for peptide mapping and studies of protein structure and conformational changes._x000D_ Thermolysin has been shown to have a prosequeence that acts as an intramolecular chaperone in vivo. It has also been used in a study to investigate the effects of sodium chloride on thermal stability and catalytic activity._x000D_ Thermolysin is also commonly used for the commercial synthesis of N-(benzyloxycarbonyl)-L-aspartyl-L-phenylalanine methyl ester, the precursor for the artificial sweetener aspartame._x000D_ Packaging_x000D_ 1 g in glass bottle_x000D_ 100, 250 mg in glass bottle_x000D_ 25 mg in poly bottle_x000D_ Quality_x000D_ Contains many extraneous enzymes._x000D_ Unit Definition_x000D_ One unit will hydrolyze casein to produce color equivalent to 1.0 μmole (181 μg) of tyrosine per min at pH 7.5 at 37 °C (color by Folin-Ciocalteu reagent)._x000D_ Physical form_x000D_ lyophilized powder containing calcium and sodium acetate buffer salts_x000D_ Preparation Note_x000D_ The pH optimum is 8.0 and the optimal temperature for activity is 70 °C. Considerably stable from pH 5 to 9.5. Thermolysin has a low cleavage specificity, therefore, it produces a number of short fragments that are suitable for sequencing. Preferential cleavage: X-cleavage-Y-Z where X=any amino acid; Y=Leu, Phe, Ile, Val, Met, Ala and Z is any amino acid other than Pro. Cleavage N-terminal to Leu is preferred over cleavage of N-terminal to Phe which is preferred over the others.