Structural Damage of Gamma-irradiated Ribonuclease Revealed by Thin-layer Isoelectric Focusing

Summary

Ribonuclease, irradiated with ⁶⁰Co γ-rays in dilute aqueous solution or in the dry state, has been investigated with respect to its charge and size properties. Thin-layer isoelectric focusing revealed extensive change in irradiated RNase; new enzymatically-active components, mainly with isoelectric points lower than in unirradiated RNase were observed. Thin-layer gel chromatography indicated the formation of aggregates which are partially active enzymatically. Aggregation depended on enzyme concentration and was less in more diluted solutions—at equal degrees of inactivation. Structural damage in the so-called ‘native’ monomers was revealed by thin-layer isoelectric focusing, their charge properties being distinctly modified.