Purification and some physical properties of a chymotrypsin-like protease of the larva of the hornet, Vespa orientalis.

A chymotryps in l ike endopeptidase has been purif ied by ion-exchange chromatography, affinity chromatography, and gel f i l tration. The enzyme preparation is homogeneous in the u l t r a centrifuge and disc electrophoresis. The enzyme is proved to be free f rom any other proteolytic activities. The molecular weight of the proteinase as determined w i t h several techniques (ultracentrifugation, gel f i ltration and electrophoresis wi thout dodecylsulfate) is in the range between 13000—14000; however, by dodecylsulfate gel electrophoresis a molecular weight of 23000 was obtained. The obtained physical constants of hornet chymotryps in are : sedimentation coefficient ^ o . w = 1.96 x 10~ 1 3 s, diffusion coefficient Z ^ o . w = 131 [ i m 2 s _ 1 , par t ia l specific volume v ^ 0.737 m l g _ 1 , f r ict ional rat io / / / m i n = 104 , and degree of hydrat i on = 0.1 g per g protein.