| First Author | Kamel R | Year | 2005 |
| Journal | Biochem Pharmacol | Volume | 70 |
| Issue | 7 | Pages | 1009-18 |
| PubMed ID | 16102731 | Mgi Jnum | J:102630 |
| Mgi Id | MGI:3607854 | Doi | 10.1016/j.bcp.2005.07.005 |
| Citation | Kamel R, et al. (2005) A high-affinity monoclonal antibody with functional activity against the 5-hydroxytryptaminergic (5-HT4) receptor. Biochem Pharmacol 70(7):1009-18 |
| abstractText | Splenocytes from a BALB/c mouse immunised with a synthetic peptide corresponding to the second extracellular loop of the 5-HT4 receptor were fused with SP2/O myeloma cells to produce a monoclonal antibody. The monoclonal antibody was of the IgG2b isotype. The antibody recognised the human 5-HT4(g) (h5-HT4(g)) receptor by immunoblots and by immunofluorescence on chinese hamster ovary (CHO) cells expressing this 5-HT4 receptor isoform. Epitope mapping of the antibody suggested the recognition of a conformational epitope, encompassing the N- and C-terminal fragments of the second extracellular loop. Kinetic experiments using surface plasmon resonance showed that the antibody had a picomolar affinity for its cognate peptide. Inhibition experiments using the same methodology confirmed the specificity of the interaction. The antibody at a concentration of 500 pM competitively inhibited inverse agonist GR113808 binding and showed an inverse agonist effect on the basal activity of CHO cells expressing the 5-HT4(g) receptor. The antibody decreased the effect of 5-HT at 500 and 50 pM concentrations but it increased 5-HT-induced cAMP levels at 5 pM. The dual effect of the monoclonal antibody could be ascribed to mono- or bivalent recognition of the receptor. The antibody described here is the first example of a high-affinity modulator of the 5-HT4 receptor. |
