Submitted to: Annals of the New York Academy of Sciences
Publication Type: Review Article
Publication Acceptance Date: September 18, 1997
Publication Date: N/A
SchistoFLRF-amide is a member of a subfamily of insect FMRFamide-related peptides that share the sequence XDVXHXFLRFamide and which are referred to as myosuppressins. Myosuppressins have been identified in a diverse number of insect species including the cockroach, locust, fruit fly, and tobacco hornworm. Members of this subfamily are potent inhibitors of insect cardiac and visceral muscle, and in addition have effects on skeletal muscle, longitudinal flight muscle, and salivary glands. Bioassays and binding assays have shown that the His residue in the truncated analogue HVFLRFamide is critical for the retention of inhibitory biological activity, whereas VFLRFamide, in which inhibitory biological activity is lost, is the minimum sequence for binding of comparable affinity to the parent compound. A number of modifications have been made in the N-terminal His residue to examine the importance of the irnidazole group of fhistidine for biological activity. Benzethonium chloride (Bztc) is a nonpeptide agonist of the PDVDHVFLRFamide receptors. Bztc mimics the physiological effects of PDVDHVFLRFamide in being able to reversibly inhibit proctolin-induced, neurally evoked and spontaneous contractions of locust oviduct. In addition, Bztc binds to both high- and low-affinity receptors of locust oviduct membrane. Bztc is therefore recognized by the binding and activation regions of these receptors. This discovery provides a unique opportunity within insects to target a peptide receptor for the development of future pest management strategies.