Submitted to: Peptides
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2006
Publication Date: 11/1/2006
Citation: Predel, R., Russell, W.K., Neupert, S., Russell, D.H., Esquivel, J.F., Nachman, R.J. 2006. Identification of the first neuropeptides from the CNS of Hemiptera: CAPA peptides of the southern green stinkbug Nezara viridula (L.). Peptides. 27:2670-2677.
Interpretive Summary: Because of problems with the development of resistance to conventional pesticides, there is a critical need for new concepts and alternative approaches in controlling insect pests. The basic premise of this research is that neuropeptides (short chains of amino acids) serve as potent messengers in insects to regulate vital functions. Nevertheless, neuropeptides in and of themselves hold little promise as pest control agents because of susceptibility to being degraded in the target pest. Neuropeptide mimics must be designed that resist degradation by enzymes in the digestive tract and blood of pest insects and interact with the active site within agricultural or medical pests by over-activating or blocking critical, neuropeptide-regulated life functions. The first step is to identify neuropeptide structures in specific insect pests. We report on the identification of the first neuropeptides from the central nervous system of a true ‘bug’. Specifically, we have used state-of-the-art analytical techniques to determine the structures of three peptides from an agricultural pest, the southern green stink bug. Two of the peptides are associated with regulation of water balance in other insects and one is associated with the regulation of a hibernation-like state that enhances winter survival in moths. This work represents an important milestone and lead in the development of practical neuropeptide-like substances that will effectively control insect pests in an environmentally friendly fashion.
Technical Abstract: A direct mass spectrometric investigation of nerve homologs of the abdominal perisympathetic organs was employed to reveal the first and complete sequences of CAPA peptides from a hemipteran species, the Southern Green Stinkbug Nezara viridula. Side-chain fragmentations allowed the assignment of internal Leu/Ile; on-plate acetylation was used to distinguish between the mass-related Lys and Gln. The following sequences were obtained: DQLFPFPRV-NH2 (CAPA-PVK-1), EQLIPFPRV-NH2 (CAPA-PVK-2), and NGSAGNGGLWFGPRL/I-NH2 (CAPA-PK). CAPA-PVKs are associated with the regulation of diuresis in insects, and identification of those native to a hemipteran will provide the experimental basis to better understand regulation of water balance in this family of insects.