|Nachman, Ronald - Ron|
Submitted to: Peptides
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2004
Publication Date: 1/1/2005
Citation: Nachman, R.J., Vercammen, T., Williams, H., Kaczmarek, K., Zabrocki, J., Schoofs, L. 2005. Aliphatic amino diacid Asu functions as an effective mimic of Tyr(SO3H) in sulfakinins for myotropic and food intake-inhibition activity in insects. Peptides. 26:115-120. Interpretive Summary: Neuropeptides are short chains of amino acids (the building blocks of proteins) that regulate aspects of reproduction, development, water balance, digestion, and feeding behavior that are critical for insect survival. Nevertheless, these insect peptides in and of themselves hold little promise as insect control agents because of susceptibility to being degraded in the target insect, and inability to pass through the outside skin (cuticle) and/or digestive tract of the insect. We must design neuropeptide mimics that resist degradation by enzymes in the digestive tract and blood of insects and interact with the active site within the pest insect to either over-stimulate or block critical, neuropeptide-regulated functions. The work describes two readily available substances that can function as effective and stable mimics of a critical but unstable portion of "sulfakinin" neuropeptides, which inhibit the feeding response in a number of insects. The information is invaluable in the design of biostable mimics capable of disrupting feeding behavior in pest insects. The work brings us one step closer to the development of practical neuropeptide-like substances that will be effective in controlling pest insects in an environmentally friendly fashion.
Technical Abstract: The aliphatic amino diacid alpha-aminosuberic acid can function as an effective, stable mimic of the hydrolysis-susceptible Tyr(SO3H) group in sulfakinin neuropeptide analogues for both hindgut contractile activity in a cockroach and food-intake inhibition activity in the desert locust. In the analogue, the acidic sulfate group is replaced with an acidic carboxyl group. The degree of activity of sulfakinin analogues is correlated with the carboxyl/alpha-carbon distance in the cockroach hindgut contractile assay. The results represent an important step in the design and synthesis of biostable, sulfakinin analogs that could potentially suppress the feeding behavior of destructive insect pests of agricultural importance.