Antigens in Insulin Determinants of Specificity of Porcine Insulin in Man

Porcine insulin, which is distinguished from human insulin only in the amino acid at the C terminal of the B chain, is antigenic in man. Even if the last amino acid or the last eight amino acids are removed from the C terminus of the B chain of insulin, the altered insulin still reacts with human antibodies to porcine insulin; thus, the antigenic determinant of porcine insulin is located in a part of the molecule where the amino acid sequence is the same as it is in the corresponding part of the human insulin molecule.