Neil S. Orenstein

Esterase and protease activity of purified guinea pig basophil granules

Abstract Highly purified granules of circulating guinea pig basophilic leukocytes were extracted with 0.1% Triton X-100 to yield a mixture of esterases-proteases including caseinolytic activity. By selective inhibition both trypsin- and chymotrypsin-like serine hydrolases have been identified. Sigmoidal pH dependences for hydrolysis of p-tosyl-L-arginine-methyl ester and N-benzoyl-L-tryosine-ethyl ester were observed for both intact granules and Triton granule extracts. Preliminary studies indicate that the enzymes are not solubilized even after Triton X-100 treatment of the granules.

Plasminogen activator and MIF-like activities in Kirsten virus transformed mouse NIH culture fluids

Abstract Kirsten virus transformed mouse NIH cells produce both a macrophage migration inhibition activity for guinea pig and mouse peritoneal exudate cells and a plasminogen activator. The migration inhibition factor activity exhibited thermal stability up to 80°C while the plasminogen activator was inactivated after 15 minutes at 70°C. Separation of these activities was achieved by absorption of the migration inhibition activity on agarose-fucosamine or high speed centrifugation.