TY - JOUR
T1 - Catalytic and ligand binding properties of bovine trypsinogen and its complex with the effector dipeptide Ile-Val - A comparative study
AU - Antoninia, Eraldo
AU - Ascenzi, Paolo
AU - Bolognesi, Martino
AU - Guarneri, Mario
AU - Menegatti, Enea
AU - Amiconi, Gino
PY - 1984/9
Y1 - 1984/9
N2 - Steady-state and pre-steady-state kinetic data for the trypsinogen catalyzed hydrolysis of a series of synthetic substrates (i.e. p-nitrophenyl esters of N-α-carbobenzoxy-L-amino acids) have been obtained as a function of pH (3.4-8). Moreover, the effect of ethylamine on the hydrolysis of a neutral substrate and benzamidine binding have been extensively studied. In order to obtain direct information on the transition of trypsinogen to a β-trypsin-like structure, the role of the effector dipeptide Ile-Val on the catalytic and ligand binding properties of the zymogen has been investigated. Kinetic and thermodynamic data for β-trypsin and α-chymotrypsin are also reported for the purpose of an homogeneous comparison of the various (pro)enzymes. Under all the experimental conditions, kinetic data for (pro)enzyme catalysis are consistent with the minimum three-step mechanism: {Mathematical expression} involving the acyl intermediate E.P. In the presence of Ile-Val dipeptide, trypsinogen assumes catalytic and ligand binding properties that are reminiscent of activated β-trypsin. This is at variance with free trypsinogen, which shows a α-chymotrypsin-like behavior. The large differences in the results of kinetic and thermodynamic measurements for free trypsinogen, as compared to its binary adduct with Ile-Val, can be ascribed to the substantial differences in the two molecular species, which include the spatial orientation of Asp189.
AB - Steady-state and pre-steady-state kinetic data for the trypsinogen catalyzed hydrolysis of a series of synthetic substrates (i.e. p-nitrophenyl esters of N-α-carbobenzoxy-L-amino acids) have been obtained as a function of pH (3.4-8). Moreover, the effect of ethylamine on the hydrolysis of a neutral substrate and benzamidine binding have been extensively studied. In order to obtain direct information on the transition of trypsinogen to a β-trypsin-like structure, the role of the effector dipeptide Ile-Val on the catalytic and ligand binding properties of the zymogen has been investigated. Kinetic and thermodynamic data for β-trypsin and α-chymotrypsin are also reported for the purpose of an homogeneous comparison of the various (pro)enzymes. Under all the experimental conditions, kinetic data for (pro)enzyme catalysis are consistent with the minimum three-step mechanism: {Mathematical expression} involving the acyl intermediate E.P. In the presence of Ile-Val dipeptide, trypsinogen assumes catalytic and ligand binding properties that are reminiscent of activated β-trypsin. This is at variance with free trypsinogen, which shows a α-chymotrypsin-like behavior. The large differences in the results of kinetic and thermodynamic measurements for free trypsinogen, as compared to its binary adduct with Ile-Val, can be ascribed to the substantial differences in the two molecular species, which include the spatial orientation of Asp189.
UR - http://www.scopus.com/inward/record.url?scp=0021340579&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021340579&partnerID=8YFLogxK
U2 - 10.1007/BF00222487
DO - 10.1007/BF00222487
M3 - Article
C2 - 6708945
AN - SCOPUS:0021340579
VL - 60
SP - 163
EP - 181
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
SN - 0300-8177
IS - 2
ER -