Immunogen sequence: FVSLKKLCCT TDNNKQIHKI HRDSGDNSQT EPHSFRYKNR RKESIDVKSI SSRGSDAPSL QNRRYPS. Cyclic nucleotide phosphodiesterases (PDEs) catalyze hydrolysis of the 5-prime,3-prime-cyclic nucleotides cAMP and cGMP to the corresponding nucleoside 5-prime