Cross-reactivity study of oxytocin antibodies with oxytocin and its analogues modified in the cyclic part of the molecule

Abstract

The specificity of oxytocin antibodies prepared by immunizing a pig with oxytocin that had been bound to thyreoglobulin by means of carbodiimide, was investigated using oxytocin analogues modified in position 1,2,4 and 6. All the modifications (deamination, substitution of sulfur in the disulfide bridge by a methylene group, methylation of the OH group of tyrosine or the substitution of the amino acid in this position and in position 4) resulted in analogues with a lower affinity to the antibodies than that of oxytocin.