Antigenic specificity of a new and potent somatostatin antiserum.

The specificity of a new somatostatin antiserum (Ab 6) has been investigated using eight different peptide analogues. For this purpose, somatostatin and all the analogues were tested, in an equimolar concentration range, for their ability to displace 125I-tyr1-somatostatin from its binding to antibodies. Analysis of the displacement curves shows that antiserum Ab 6 predominantly recognizes changes at the central aminoacid sequence of the somatostatin molecule. Its ligand specificity seems to be similar to that of other somatostatin antisera previously described (R-141 and A-101).