Identification of an antigenic determinant of mouse lactate dehydrogenase C4

A peptide bearing an antigenic determinant of the sperm-specific lactate dehydrogenase C₄ isozyme (LDH-C₄) has been isolated from a tryptic digest of the whole protein. This peptide, comprising residues 152–159 (MC_152–159), reacts with rabbit anti-mouse LDH-C₄. Immunization of rabbits with synthetic MC_152–159 conjugated to bovine serum albumin induces an immune response which is specific for the peptide. Anti-MC_152–159 IgG binds ¹²⁵I-labeled mouse LDH-C₄ and competition experiments demonstrate the specificity of this antigen-antibody reaction.