ROCHESTER, Minn. -- A Mayo Clinic researcher has discovered a target site within malaria-carrying mosquitoes that could be used to develop pesticides that are toxic to the Anopheles gambiae mosquito and other mosquito species. It would not affect humans and other mammals. If supported by further studies, the findings could offer a safer and more effective control of mosquito-borne diseases such as malaria.
Yuan-Ping Pang, Ph.D., a chemist and expert in computer-aided molecular design at Mayo Clinic, identified two unique amino acid residues called cysteine (286) and arginine (339). These exist in three mosquito species and the German cockroach.
Dr. Pang's findings are significant because the residues could potentially be used as a target site for a pesticide that would incapacitate only insects that carry these residues, which do not exist in mammals. The findings appear in the current issue of PLoS ONE, a new, peer-reviewed, open-access journal published by the Public Library of Science.
"These findings suggest that new pesticides can be designed to target only the mosquito enzyme. Such pesticides could be used in small quantities to harm mosquitoes, but not mammals," Dr. Pang says. "We've developed a blueprint for a pesticide that could incapacitate malaria-carrying mosquitoes. We are currently making a prototype of the new pesticide."
Most pesticides today work by crippling the serine residue, which is another amino acid of the enzyme acetylcholinesterase and is located at the active site of the enzyme. This serine residue is present in both insects and mammals and therefore, any pesticide targeting this amino acid affects both insects and mammals.
Acetylcholinesterase is a vital enzyme to both insects and mammals. It breaks down the neurotransmitter acetylcholine, which is a primary neurotransmitter in the brain that is associated with memory and cognition.