The L isomers of esters, amides, and hydrazides of the general formula RCONHCHRICORz where R = CHS-, CsHb---, etc., RI = CsH&H2-, p-HO-&H&H-, etc., and Rz = -0CH3, -NH*, or -NHNH2, are known to be hydrolyzed by chymotrypsin (l-6). It has now been found that the corresponding hydroxamides, RCONHCHRICONHOH, where R1 = CsH&Hz--, are also hydrolyzed by this enzyme (Table I). Aside from the obvious ...

Previous communications from this Laboratory have shown that the inhibition of cy-chymotrypsin by diisopropyl fluorophosphate (DFP) is a stoichiometric reaction that comprises the introduction of a single diisopropyl phosphate group into the molecule of cu-chymotrypsin, the elimination of fluorine as HF, and the production of an undenatured, crystallizable, inhibited enzyme protein (l-3). Sever...

As recently reported, the behavior of acetyl chymotrypsin with ethanol consists in a rapid transfer of the single acetyl group to that alcohol with the formation of ethyl acetate (1). Thus, the splitting of nitrophenyl acetates by chymotrypsin, faster in ethanolic than in aqueous solutions, may be explained by the formation of acetyl chymotrypsin as an intermediate and its subsequent preferenti...

The alpha-2 macroglobulins from human serum and plasma were isolated by Bio-Gel P-300 and A5m gel filtration. The material showed a single peak on sedimentation velocity ultracentrifugation, a mol wt of 650,000 by sedimentation equilibrium ultracentrifugation, and a major precipitin arc in the alpha-2 macroglobulin region by immunoelectrophoresis against whole human serum. Two bands were observ...

The possibility of generating protein folds at the stage of backbone assignment using structural restraints derived from experimentally measured cross-hydrogen bond scalar couplings and secondary chemical shift information is investigated using as a test case the small alpha/beta protein chymotrypsin inhibitor 2. Dihedral angle restraints for the phi and psi angles of 32 out of 64 residues coul...

Protein food modulates the activity of proteases of the midgut gland of Penaeus vannamei. Shrimp fed with food containing 15, 30 and 50% protein exhibited differences in trypsin and chymotrypsin activity and trypsin mRNA levels. Shrimp fed with 30% protein showed higher trypsin and chymotrypsin activities than those fed 15 or 50% protein. An additional paralogue trypsin was observed with electr...

Insolubilized cr-chymotrypsin bound to porous glass gel has been prepared. The kinetic behavior of this fixed enzyme proved to be the same as that of the free enzyme. The effects of aprotic dipolar organic solvents on the kinetics of cr-chymotrypsin-catalyzed hydrolysis were successfully studied using this insolubilized enzyme at concentrations up to 95% v/v dioxane, taking advantage of the ina...

A population of identical proteins has the same amino acid sequence, but there may be subtle differences in local folding that lead to variations in activity. Single molecule studies allow us to understand these subtle differences. Single molecule experiments are usually time consuming and difficult because only a few molecules are observed in one experiment. To address this problem, we have de...

Chymotrypsin enhanced fowlpox virus plaque formation in chick embryo cell cultures. A simplified plaque assay for fowlpox virus is described. Plaques were produced in 3 days when chymotrypsin was included in a serum-free fluid overlay. Plaques were also produced in 5 to 6 days under an agar overlay when a medium containing fetal calf serum was employed. Kinetics of plaque formation were also st...