Production and evaluation of monospecific antibodies for a processing-independent sequence of human progastrin

Abstract

We have produced a series of monospecific antibodies in five rabbits by immunization with a peptide corresponding to the preprogastrin sequence 76–88. Both antibody titres (0.2 to 3.0x10⁶), indexes of heterogeneity (−1.0), and binding affinities (K°eff-0.2 to 3.7X10¹² lxmol⁻¹) were very high. The specificity for the N-terminus of the progastrin fragment was unique because even a conservative amino acid substitution five positions from the centre of binding diminished the binding by 90% for all antibodies. We conclude that these monospecific antibodies are well suited for development of a processing-independent analysis of progastrin and its products.

Key Words:

• monoclonal antibodies
• post-translational processing
• radioimmunoassay