Molecular and Kinetic Properties of Two Acetylcholinesterases from the Western Honey Bee, Apis mellifera
Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Acetylcholinesterase (AChE, EC is a critical enzyme in the cholinergic synapses and neuromuscular junctions of both vertebrates and invertebrates that regulates the level of the neurotransmitter acetylcholine and terminates nerve impulses [1]. AChE is a key enzyme in the insect nervous system, in which the cholinergic system is essential [2], and is the target of organophosphate (OP) and carbamate (CB) insecticides. Reduced sensitivity of AChE has been reported as one of the major resistance mechanisms against OP and CB insecticides in many arthropods.