Open AccessMonoclonal antibodies against different epitopes of peptide hormones
Author(s) -
JURZAK Mirek,
BOER Rainer,
FRITZSCH Günter,
KOJRO Elzbieta,
FAHRENHOLZ Falk
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb15543.x
Subject(s) - epitope , monoclonal antibody , hapten , chemistry , peptide , tripeptide , antigen , antibody , arginine , biochemistry , biology , amino acid , immunology
In order to produce monoclonal antibodies directed against different epitopes of the neurohypophyseal hormone vasopressin, the hormone was coupled to carrier proteins via photoreactive groups at different positions in the vasopressin sequence: [2‐(4‐azidophenylalanine), 8‐arginine]vasopressin (peptide P1, photoreactive group at position 2) and desamino‐[8‐ N 6 ‐(4‐azidophenylamidino)lysine]vasopressin (peptide P2, photoreactive group at position 8) were conjugated to thyroglobulin by flash photolysis. Monoclonal antibodies against these conjugates bound {[ 3 H]8‐arginine}vasopressin with dissociation constants ranging over 40–400 nM. Epitope analysis by means of competitive ELISA showed that the monoclonal antibody obtained with peptide P1 as hapten was directed against the C‐terminal acyclic tripeptide when its conformation was stabilized by interaction with the disulphide‐linked cyclic hexapeptide. In contrast, the epitope analysis of three monoclonal anti‐(peptide P2) antibodies demonstrated that they recognized antigenic determinants in the cyclic hexapeptide ring, mainly the hydrophobic surface formed by Tyr 2 and Phe 3 . Our results suggest that monoclonal antibodies against different epitopes in small peptide hormones can be generated selectively by using photoreactive peptides in such a way that different antigenic sites are exposed in the hapten‐carrier conjugate.