A -Benzoyl-L-arginine-p-nitroanilide

Activity 1.16 X 10 2 BAPA units (BAPA refers to A -benzoyl-L-arginine p-nitroanilide). 

Trypsin (5 xg/ml), type IX from porcine pancreas, and 0.375 mM A-a-benzoyl-L-arginine-p-nitroanilide (l-BAPNA) were added to a 96-well assay plate containing... 

Abbreviations ADA, adenosine deaminse BAEE, N,a-benzoyl-L-arginine ethyl ester, BTEE, N,oc-benzoyl-L-tyrosine ethyl ester BTNA, N,a-benzoyl-L-tyrosine-p-nitroanilide ZAPA, N,a-benzoylcarbonyl-L-arginine-p-nitroanilide. 

Trypsin, chymotrypsin, and cathepsin C (all from bovine), and the synthetic substrates glycyl-L-phenylalanine p-naphtylamide (GPNA), 4-phenylazo benzyloxy-car-bonyl-pro-leu-gly-pro-D-arg (PZ-peptide), N-benzoyl-L-tyrosine ethyl ester (BTEE), and Na-benzoyl-DL-arginine p-nitroanilide (BAPNA), were purchased from Sigma Chemical Co (St. Louis, MO). Fresh bluefish (Pomatomus saltatrix) and sheephead samples were purchased from a local fish market (Waldman Plus, Montreal, PQ) and kept in iCe until ready for use. 

A substrate L-benzoyl arginine p-nitroanilide hydrochloride was hydrolyzed by trypsin, with inhibitor concentrations of 0, 0.3, and 0.6 mmol l-1. The hydrolysis rates obtained are listed in Table 3.3 [5], Determine the inhibition mechanism and the kinetic parameters (Km, Vmax, Kt) of this enzyme reaction. 

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