Structure-activity relationship of memory enhancing peptide ZNC (C) PR analogs

ZNC(C)PR has been found to be a new neuropeptide in rat brain as a significant enhancer of learning and memory. In this work, the structure-activity relationship of ZNC(C)PR was studied. First, the roles of every residue in ZNC(C)PR were investigated theoretically and analogs were designed according to the predicted conformational properties. Five analogs were synthesized following the design. Passive avoidance behavior tests in rats showed that NIPR, NVPR, and NAPR have positive effects to facilitate memory, while NSPR has no effect, and DLPR has somewhat inhibitory effect. As the experimental results are in good agreement with that of theoretical calculations, it is suggested that further research may help us to understand more details on the structure-activity relationship of ZNC(C)PR and provides a way for further design of potent agonist, antagonist and possible nonpeptide mimetics of ZNC(C)PR.