[Radiation inactivation of alpha-chymotrypsin in aqueous solutions. Effect of irradiation conditions].
A comparative study was made of inactivation by gamma- and beta-radiation of alpha-chymotrypsin within a wide range of its initial concentrations (from 10(-4) to 10(-7) M). The regularities of gamma- and beta-inactivation are the same, and distinctions, if any, are due to a greater radiation effect of beta-rays on dilute enzyme solutions (less than or equal to 5 X 10(-6) M). The inactivation of alpha-chymotrypsin by radiation proceeds either via primary molecule unfolding followed by degradation of the most accessible and radiosensitive amino acid residues (pH 7.8) or, to a greater extent, via direct disruption of amino acid residues which can probably be random (pH 3.0). Calcium ions stabilize, on the whole, the enzyme molecule upon irradiation.
D000596:Amino Acids / Q000528:radiation effects; D001610:Beta Particles; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D012996:Solutions
D000596:Amino Acids; D012996:Solutions; D002918:Chymotrypsin
Radiatsionnaia inaktivatsiia alpha-khimotripsina v vodnykh rastvorakh.Vliianie usloviĭ oblucheniia.