The Specific Peptidase and Esterase Activities of Chymotrypsin

Relationship between Active Sites and Polymerization Sites in α-Chymotrypsin*

“…The kinetic study (Inagami and Sturtevant, 1965), using stopped-flow techniques up to 6% enzyme concentration, has concluded that the dimeric and trimeric forms of the enzyme must also possess catalytic activity. The present equilibrium study (see also Sarfare and Kegeles, 1965) shows that within experimental error the enzyme polymerizes identically in the presence or absence of the competitive inhibitor 5-phenylpropionate (Kaufman and Neurath, 1949;Neurath and Gladner, 1951). This can be true only if 5-phenylpropionate binds equally well to a site on monomer, to either of two sites on dimer, and to each of three sites on a trimer molecule.…”

“…Theoretical Predictions. The calculations of weightaverage molecular weights are based on reported values for the dissociation constant of the complex between 3-phenylpropionate and the enzyme (Kaufman and Neurath, 1949;Neurath and Gladner, 1951) and on reported values for the dissociation constants for the dimer and trimer (Rao and Kegeles, 1958). Kaufman and Neurath reported a value of K¡ = 4.5(10)~3 moles/1., and more detailed work of Neurath and Gladner revised this to Kr = 5.5(10)-3 moles/1.…”

Discovery of Stable Non-opioid Dynorphin A Analogues Interacting at the Bradykinin Receptors for the Treatment of Neuropathic Pain

“…Bestatin is a common aminopeptidase inhibitor of leucine aminopeptidase, aminopeptidase B, and aminopeptidase N. 14,15 Chymotrypsin is a serine protease that cleaves after aromatic amino acids such as Tyr, Phe, and Trp. 16 Chymostatin is a known inhibitor of chymotrypsin, as well as cathepsin B, and cathepsin D, a cysteine protease that cleaves after a Phe residue. 17 Phenylmethanesulfonyl fluoride (PMSF) is another serine protease inhibitor that also targets chymotrypsin but will also inhibit papain and thrombin.…”

“…Because ligand 1 was degraded at the N-terminal peptide bond, an aminopeptidase may be responsible for the degradation. Bestatin is a common aminopeptidase inhibitor of leucine aminopeptidase, aminopeptidase B, and aminopeptidase N. , Chymotrypsin is a serine protease that cleaves after aromatic amino acids such as Tyr, Phe, and Trp . Chymostatin is a known inhibitor of chymotrypsin, as well as cathepsin B, and cathepsin D, a cysteine protease that cleaves after a Phe residue .…”

Systematic Fractionation of Swine Pancreatic Hydrolases. I. Fractionation of Enzymes Soluble in Ammonium Sulfate Solution at 0.40 Saturation*

“…Quantitative Assays for Enzymes. Tryptic and chymotryptic activities were measured by a continuous titration method6 at a constant pH of 7.9 using BAEE (Schwert et al, 1948) for trypsin and ATEE (Kaufman et al, 1949) for chymotrypsin and enzymes with chymotrypsinlike activity. Proteolytic activity against native egg albumin was measured by the same procedure.…”