Bovine albumin-like protein in commercial human albumin for clinical use.

We have demonstrated that several lots of commercial human serum albumin (HSA), prepared for clinical use by two manufacturers, reacted with anti-bovine whole serum in the double-diffusion test. The antigenic proteins were purified by affinity chromatography from these HSA lots and their chemical and immunological properties characterized. The purified proteins showed the same molecular weight as HSA and bovine serum albumin (BSA). By CNBr treatment and trypsin digestion, the purified protein produced the same fragments as BSA. Moreover, the purified protein had an amino acid composition very similar to BSA and also 30 residues identical to those of the N-terminal amino acid sequence of BSA. In addition, it was shown that heterophilic Hanganutziu-Deicher antigenicity was present in the purified protein. The protein reactive against-bovine whole serum, contained in commercial HSA, was called BSA-like protein.