title: [Enzyme inactivation after exposure to mechanical factors].
abstract: Kinetics of decreasing proteolytic activity of subtilisin and trypsin during grinding of powders was studied. The enzymes were ground in a ball laboratory vibromill for 1-80 min within the temperature range 80-300 K in the air or helium. Proteolytic activity of the enzymes measured by the splitting of low molecular p-nitroanilide substrates decreases with the increase of the treatment time according to the equation of the first order. By means of titration of trypsin active centres a decrease of their number after grinding was shown. Kinetic parameters in Michaelis-Menten equation were determined for trypsin enzymic reaction. It was found that the value kappa kat decreased with an increase of the time of mechanical treatment.
mesh_terms: D000495:Allosteric Site; D006358:Hot Temperature; D006868:Hydrolysis; D007700:Kinetics; D011489:Protein Denaturation; D013381:Subtilisins; D014357:Trypsin; D014732:Vibration
chemical_list: D013381:Subtilisins; D014357:Trypsin
vernacular_title: Inaktivatsiia fermentov pri mekhanicheskikh vozdeĭstviiakh.