[Purification, heterogeneity and some properties of T2 bacteriophage lysozyme].

Free T2 bacteriophage lysozyme is isolated and purified from 80 l portion of phagolysate by means of ballast protein and bacterial debris precipitation with rivanol, two-stage fractionation on amberlit IRC-50 and chromatography on CM-Sephadex C-50. Purified enzyme is homogenous under polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate, it has a molecular weight value similar to that in the literature. A presence of two active enzyme forms (I and II) is demonstrated. They can be separated by means of analytical electrophoresis in polyacrylamide gel at pH 4,5 and of ion-exchange chromatography on Amberlite IRC-50. T2 lysozymes I and II do not differ in their amino acid composition, ORD parameters, and they are not interconversible. Heterogeneity of phage lysozyme is shown not to be an artefact and to be due neither to heterogeneity of the initial phage poluation, nor to aggregation and to oxidation of enzyme SH-groups. The content of alpha-helix regions, as estimated by ORD is higher in phage lysozyme than in hen egg-white lysozyme, which evidences that these proteins are non-homologous.