Purification and characterization of chymotrypsinogen from pancreas of Japanese quail (Coturnix coturnix japonica).

1. A chymotrypsinogen from pancreas of Japanese quail (Coturnix coturnix japonica) was purified by acid extraction, salt fractionation and chromatographic separation on CM-cellulose and Sephadex G-100, and gave a single protein band on SDS-PAGE. 2. Quail chymotrypsinogen had a mol. wt of 26,100 calculated from amino acid composition data, an isoelectric point of 7.68, a Km of 3.1 mM and K0 of 40.7 sec-1 for tyrosine ester substrate. 3. The activated chymotrypsinogen of quail had a maximum activity at pH 7.0-8.0 and at 45 degrees C, and was stable at pH 4.0-6.0 below 55 degrees C. 4. Comparison of quail and bovine chymotrypsinogens indicates that the activities of the enzymes from quail and bovine are more constant than their physical characteristics.