ANTIGENICITY OF THE 139-149 ALPHA(S1)-CASEIN REGION IN DIFFERENT SPECIES REVEALED BY ELISA AND IMMUNOBLOTTING USING ANTIPEPTIDE ANTIBODIES

The antigenicity of the 139-149 alpha(S1)-casein region has been studi ed by using polyclonal antibodies raised against four different peptid es. Two antisera, directed against the bovine 141-148 and 139-149 alph a(S1)-casein sequences, were found to be cow-specific in competitive E LISA tests. By immunoblotting, the recognized components corresponded to a set of minor bands distinct from the bovine alpha(S1)-casein, als o detected by polyclonal antibodies against purified bovine alpha(S1)- casein fraction. The anti-(141-147) sequence stretch, common to bovine , water buffalo, caprine, and ovine alpha(S1)-casein, recognized the m ain alpha(S1)-casein components from the four milks, whereas the anti- (141-148) sequence stretch, present in water buffalo, caprine, and ovi ne alpha(S1)-casein, detected only minor alpha(S1)-casein components. Applications of these polyclonal antipeptide antibodies are suggested for the detection of bovine milk in mixture with milk from different s pecies and for the evaluation of specific minor casein components.