Isolation and Characterization of Four Basic Proteins from Horse Eosinophilic Granules

Abstract Four new basic proteins were isolated from horse eosinophils and purified. The eosinophils release these proteins after permeabilization with saponin and degranulation stimulized by guanosine 5′-O-thiotriphosphate. The proteins were separated and purified on a Superose P12- and a Mono S-column by fast protein liquid chromatography. The amino acid composition, the relative molecular mass, the isoelectric point and the partial N-terminal sequence of the four proteins were determined. Papain-activation and ribonuclease activity of the four proteins were tested for comparison with the human eosinophil basic granular proteins. The cytotoxicity of the hole granular extract and of the isolated basic proteins against Escherichia coli K12 was also studied.