An insoluble aggregate of commercially available bovine serum albumin shows antiproteolytic activity

Chemical aggregation of bovine serum albumin by extensive chemical crosslinking with glutaraldehyde yielded an insoluble protein preparation with significant antiproteolytic activity. This was presumably due to the presence of alpha 2-macroglobulin in bovine serum albumin preparations. Chemical crosslinking of bovine serum albumin under optimum conditions was found to increase its antitryptic activity by about four times. The results indicate that enhanced rigidity of alpha 2-macroglobulin structure increases its antitryptic activity.