Isolation and characterization of adult bovine heart muscle chalones

A three-step purification procedure for the isolation of heart muscle chalones is described. The method uses ultrafiltration followed by concanavalin A-Sepharose affinity chromatography and subsequent sucrose density gradient centrifugation. Analytical ultracentrifugation of the highly purified chalone fraction indicated a sedimentation coefficient of 16.7 S and an average Mr of 715,527. Chemical analyses have confirmed this protein to be a glycoprotein, and polypeptide analysis indicated the involvement of identical subunits in its composition. In vivo studies confirmed that the chalone isolated from adult bovine hearts inhibits DNA synthesis of newborn hamster hearts. In addition, it was found to be tissue and not species specific and had no cytotoxic effects on the target cells.