2011 Annual Report 1a.Objectives (from AD-416) Establish mutually productive collaboration to discover and develop target-specific pesticides to control parasitic arthropods impacting animal and public health. 1b.Approach (from AD-416) We will provide enzymatically active recombinant acetylcholinesterases from several economically important pests, beginning with rBmAChE1, the major acetylcholinesterase (AChE) of Rhipicephalus (Boophilus) microplus, and following with AChEs from other pest species, including sand flies, ticks, and biting flies. Cooperator will screen various ligands for specific binding to the AChEs that result in blocking the enzymatic activity. It is also possible that other binding sites may result in pesticidal activity without blocking enzymatic activity. Candidate control ligands will, in turn, be provided to KBUSLIRL scientists for in vivo and in vitro screening to test control efficacy against target pests. 3.Progress Report We recently initiated this agreement and have sent recombinant acetylcholinesterases, rBmAChE1, rBmAChE2, and rBmAChE3 of Rhipicephalus microplus for biochemical studies. The objective of the studies is to identify and characterize biochemical differences between the proteins as a step toward elucidating their functions in vivo. Determination of differences in properties and function may allow specific targeting for development of new pest control technologies with reduced environmental and off-target toxic effects. Project progress is monitored by email and teleconferences between the ARS scientist and the cooperator.