Abstract

Phosphodiesterase 5 (PDE5) is a catalytic enzyme for degradation of cyclic guanosine monophosphate (cGMP) in human smooth muscle cells. Inhibition of this enzyme by certain chemicals including sildenafil, vardenafil and tadalafil, is considered a breakthrough treatment of erectile dysfunction. Unfortunately, these drugs are associated with several side effects. In this study, another strategy is adopted in the inhibition of the PDE5 enzyme by using a monoclonal antibody (Mab) against the enzyme. The Mab was prepared by immunizing a mouse, taking the spleen to make single cell suspension of lymphocytes. Hybridoma cells were obtained by fusion of BALB/c myeloma cells with the immunized lymphocytes using the polyethylene glycol method. Several clones were produced that have been separated by limiting dilution method. The antibodies were tested by enzyme-linked immunosorbent assay (ELISA) and western blot. The obtained Mab has titer of 625, immunoglobulin G1 (IgG1) isotype and 3.9 × 10⁴ mol^-1 affinity constant.

Key words: Phosphodiesterase (PDE), chemical inhibition, monoclonal antibody (Mab).