Fragmentation of human albumin with proteolytic enzymes and its antigenicity with special reference to human-specificity.

Human albumin prepared by the trichloroacetic acid method was treated with bromelin, ficin, papain, pronase or trypsin. Pronase- or trypsin-treated albumin showed four fragments on polyacrylamide disc electrophoresis. When rabbit antiserum to pronase-treated albumin was adsorbed with monkey albumin, antibody with human specificity was completely abolished, whereas anti-albumin serum adsorbed with pronase-treated albumin retained the antibody to human albumin. It was considered that antigenic site with human specificity in albumin structure was inactivated by pronase.