Inactivation of macromolecules by ionizing radiation. Deterministic single-hit or stochastic multievent process?
A stochastic theory concerning the radiation inactivation of macromolecules such as enzymes or receptors is elaborated. In contrast with the single-hit theory, which assumes a complete inactivation of the target as the result of one hit, the stochastic theory postulates that the degree of inactivation by one hit is a random variable. This distinguishing feature has been considered in order to give a possible interpretation to the observed effect of temperature on the radiation-sensitivity of enzymes. As a consequence of the progressive inactivation during irradiation, the binding affinity of a ligand for the macromolecule is impaired by irradiation. Although this property might discriminate the stochastic theory from the classical single-hit theory on the basis of a statistical analysis of experimentally obtained data, it is shown that the commonly obtained degree of inaccuracy may render the statistical test non-conclusive.
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Swillens
D008024:Ligands; D046911:Macromolecular Substances; D008956:Models, Chemical; D011506:Proteins / Q000528:radiation effects*; D011955:Receptors, Drug / Q000528:radiation effects
D008024:Ligands; D046911:Macromolecular Substances; D011506:Proteins; D011955:Receptors, Drug