Antibodies to recombinant fragment 212-276 of protein C specifically recognize the intact human molecule

The peptide fragment Pro212-Ile276 of human protein C was produced as a part of a fusion protein in Escherichia coli. The identity of the peptide was confirmed by immunoblotting experiments using specific antibodies to intact protein C. The peptide Pro212-Ile276 was isolated from the fusion protein after mild hydrolysis with formic acid by gel filtration and reverse-phase HPLC. This peptide fragment was used to produce antibodies specific for the heavy chain of protein C which recognized native protein C present in blood plasma. Antibodies to intact protein C reacted also with the Pro212-Ile276 peptide fragment, indicating that this region is immunogenic in intact protein C and may represent a native epitope.