Mp. Rolland et al., MONOSPECIFICITY OF THE ANTIBODIES TO BOVINE ALPHA(S1)-CASEIN FRAGMENT-140-149 - APPLICATION TO THE DETECTION OF BOVINE-MILK IN CAPRINE DAIRY-PRODUCTS, Journal of Dairy Research, 62(1), 1995, pp. 83-88
Comparison of the primary sequences of bovine, ovine and caprine a,, c
asein shows a deletion of eight amino acid residues in the ovine casei
n region 141-148, which is identical in the bovine and caprine protein
s except for a single difference in position 148 (Q or E). Polyclonal
antibodies raised in rabbits against the bovine casein sequence 140-14
9 (QELAYTFYPEL) appeared monospecific for bovine alpha(s1)-casein, sin
ce no antibody-antigen complex was formed with homologous ovine or cap
rine proteins. These antibodies remained unable to recognize the capri
ne sequence in the native protein even after extensive tryptic proteol
ysis. The lack of immunoreactivity of the antibodies against synthetic
caprine alpha(s1)-casein peptide 138-149 (VNQELAYFYPQL) suggested tha
t the glutamic acid residue in position 148 is essential for the antig
enic character of the bovine peptide. From these observations, the use
of these antibodies for the detection and quantitation of bovine milk
present in ovine dairy products could be extended to caprine products
.