Characterization of the Monoclonal Anti-Substance P Antibody Derived From Nc1/34



Jafariandehkordi A¹ ; Biggs DF²
Source: Medical Journal of the Islamic Republic of Iran Published:2005

Abstract

The rat-mouse heterohybridoma NC1/34 secretes a specific anti-substance P antibody (α-SP MAb). The relative affinities of this cc-SP MAb for SP, SP fragments and selective neurokinin receptor (NKR) antagonists were determined by inhibition. N-terminal fragments of SP, C-terminal mono- and di-peptide fragments of SP and NKR antagonists did not prevent α-SP MAb binding to SP-BSA conjugate bound to the plates. The relative affinities of α-SP MAb for SP and its C-terminal fragments were: SP6-11 > SP 7-11 > SP=SP5-11, SP4-11, SP3-11 and SP2-11 > SP8-11 and SP9-11. Alanine substitution studies showed that none of these peptides bound to monoclonal α-SP MAb, but all bound to polyclonal anti-SP Ab (serum). We conclude that the α-SP MAb binds to epitopic sites on SP's C-terminal. Amino acids 6 and 7, and, to a lesser extent, 8 and 9, determine affinity. The C-terminal carboxyl group has to be accessible for binding to occur.