SOURCE. Human Pancreas
Lyophilized as a solution in 0.05 M NaOAc pH5 + 0.3 M NaCl.
Redissolve with H2O.
Protein determined by method of Bradford using BSA as standard.
Store at - 20°C. Stable 9-12 months.
MW approximately 25000.
95 - 115 Units per mg of elastase protein.
Assay on elastin-remazol (EPC No. E194) 200 - 400 mesh.
One unit will hydrolyze 1 mg of substrate in 30 minutes at pH 8.8 at 37°C.
Assay buffer-substrate is 1.0 ml 0.2 M Tris pH 8.8, 5 to 15 µgm enzyme and 0.5 ml of 40 mg/ml substrate buffer in H2O. Incubate at 37°C with shaking (keep suspended) for 30 minutes. Add 3.5 ml cold H2O then filter on rapid flow paper. Read A595 on filtrate and compare to a blank not containing enzyme and to totally hydrolyzed substrate. A595 = 0.4 for 1 mg/ml totally hydrolyzed substrate at pH 8.8. This assay is detailed im Methods in the EPC Research Biochemicals Catalogue.