Dog Pancreatic Arginine Esterases : spontaneously activated on DEAE-Sephadex

Tremendous activation of arginine esterases or trypsin-like enzymes from the dog pancreas was observed during DEAE-Sephadex A-50 chromatography of the pancreatic kallikrein. The esterase activity freshly assayed was 7.5 μmoles Nα-benzoyl-L-arginine ethyl ester (BAEE)/min per gram of the pancreas. The enzymes were separated into two fractions by Ampholine isoelectric focusing, their isoelectric points being 4.6 and 4.8. The two esterases purified showed the specific activities with 4.4-7.4 μmoles BAEE/min/A280 and 20-36 μmoles Nα-p-toluenesulfonyl-L-arginine methyl ester (TAME)/min/A280, and hydrolyzed Nα-benzoyl-DL-arginine-p-nitroanilide (BApNA) and casein. The esterases were strongly inhibited by Trasylol, soybean trypsin inhibitor, kallikrein inhibitors from potatoes, etc. From chemical and enzymatic properties, both esterases seemed to be anionic trypsins of the dog pancreas.