Immunogen sequence: VVNDLFEEQT DLEKIVKKIM HRAQTLLKCE RCSVLLLEDI ESPVVKFTKS FELMSPKCSA DAENSFKESM EKSSYSDWLI NNSIAELVA. The 3',5'-cyclic nucleotides cAMP and cGMP function as second messengers in a wide variety of signal transduction pathways. 3',5'-cycli