Immunologic Properties of Biosynthetic Human Insulin in Vitro

Some immunologic properties of biosynthetic human insulin (BHI) were examined in vitro. An identical behavior was found for BHI and pancreatic human insulin as standard preparation and for A14-mono-labeled BHI and pork insulin as tracer in the insulin radioimmunoassay. BHI proved to be free of human proinsulin and C-peptide. Insulin antibodies in serum of two diabetic patients showed a preferential binding of ¹²⁵I-bovine insulin. However, the antibody titers were almost identical for A14-mono-labeled BHI and pork insulin. These studies did not reveal any characteristic immunologic properties of BHI compared with highly purified pancreatic human and pork insulin.