[The isolation of nucleases Sm1 and Sm2 in preparative amounts and a study of their antigenicity]

Two enzyme forms of endonuclease (Sm 1 and Sm 2) strain B10M1 in 60 and 100 mg respectively have been isolated from the culture fluid Serratia marcescens. The chromatographic and electrophoretic properties and N-terminal amino acid residues are different for both enzymes. The purification procedure consists of dialysis and ion-exchange chromatography on DEAE- and phosphocellulose. The yield of nucleases Sm1 and Sm2 are 14% and 28% respectively. The antigenic differences of nucleases Sm1 and Sm2 have been found by cross immunoenzyme analysis.