Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: July 18, 1996
Publication Date: N/A
Interpretive Summary: Neuropeptides are small chains of amino acids. In insects, neuropeptides act as hormones to control a wide variety of life processes such as digestion, muscular movement, excretion, etc. It is possible to exploit these chemicals to develop more effective methods of controlling pest insects. However, the neuropeptides themselves degrade easily when acted upon by enzymes in insects and do not penetrate the outside skin of insects. These studies were designed to develop mimics that retain biological activity but that overcome the problems associated with neuropeptides themselves. We describe the 3-dimensional structures required by two peptide classes to operate within the insect and utilize that information to develop closely related compounds that can mimic the action of one class and block the action of another class. We have developed a completely nonpeptide mimic of one insect peptide class that is resistant to a major process that degrades the natural peptides. We have developed a compound that, applied to the surface of the tobacco budworm moth, has effects on reproduction that are more pronounced than the neuropeptide. This work is very important in efforts to exploit neuropeptide technology in the development of a new class of pest insect control agents that will be more selective and more environmentally friendly than the conventional pesticides that are currently used to control pest insects.
Members of the insect pyrokinin/PBAN and myosuppressin neuropeptide families regulate and/or influence such physiological processes as pheromone production, oviduct contraction, digestive enzyme release and the developmental processes of egg diapause and larval pupariation in a variety of insects. However, these peptides hold little promise as pest control agents due to their susceptibility to enzymatic degradation in the target insect, and to an inability to readily penetrate the insect cuticle or gut wall. In this chapter, we discuss active conformations adopted by the peptides at the receptor site and the development of active pseudopeptide and nonpeptide mimetic analogs with enhanced resistance to peptidase attack and/or topical activity in an intact insect. Disruption of peptide-regulated processes or behavior by mimetic agonist and/or antagonist analogs could form the basis for future pest insect management strategies.