[Mechanism of the stimulating effect of protamines on the infectivity of DNA phages].

The interaction of styrin (protamine from sturgeon milt) with E. coli spheroplasts was investigated with the aid of the fluorescent probe--5-dimethylamino-1-naphthalenesulfonyl-chloride (DNS). Not less than 40% of the total (15 mug ml-1) DNA-protamine concentration was bound to spheroplasts. A part of the protein was found in the isolated membranes and inside the cell. There was a correlation between the binding of protein with spheroplasts and its biological action. The dansylation somehow decreased the protein stimulating activity in transfection.