Application

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.

Packaging

100, 250 mg in glass bottle

25 mg in poly bottle

Physical form

lyophilized powder containing calcium and sodium acetate buffer salts

Unit Definition

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).