Disease relevance of Ache

• Toxicity of cypermethrin and fenitrothion on the hemolymph carbohydrates, head acetylcholinesterase, and thoracic muscle Na+, K+-ATPase of emerging honeybees (Apis mellifera mellifera. L) [1].

High impact information on Ache

• Electrophoretic analysis in the presence of detergent demonstrated that the 14 S and 11 S peaks corresponded to aggregates of the 5 S/6 S form, whereas the 7 S peak corresponded to a hydrophilic acetylcholinesterase form which was recovered in the aqueous phase following Triton X-114 phase separation [2].
• The polymorphism of bee acetylcholinesterase was studied by sucrose-gradient-sedimentation analysis and non-denaturing electrophoretic analysis of fresh extracts [2].
• Histochemistry of acetylcholinesterase and immunocytochemistry of an acetylcholine receptor-like antigen in the brain of the honeybee [3].
• Because the antiserum against locust AChR binds in neuropiles displaying AChE activity, we conclude that this antiserum also cross-reacts with the bee's receptor [3].
• The AChE staining marked layers in the optic lobes, fibers connecting the two brain hemispheres, and fiber tracts as well as soma clusters within the protocerebrum [3].

Biological context of Ache

• Changes in neuronal acetylcholinesterase gene expression and division of labor in honey bee colonies [4].
• These findings demonstrate long-term, naturally occurring developmental downregulation of AChE gene expression in the bee brain, and suggest that this genomic plasticity can contribute to facilitated learning capabilities in forager bees [4].
• The kinetic analysis of Apis mellifera acetylcholinesterase inhibition by the carbamate pirimicarb showed that native and detergent-solubilized membrane enzyme exhibited slightly different carbamylation kinetics [5].
• These results show that the molecular structure, the mode of preparation and the source of acetylcholinesterase from the bee head should be taken into account in accurate toxicological studies [5].
• Acetylcholinesterase histochemistry, immunocytochemical staining for nicotinic acetylcholine receptors, and mapping for alpha-bungarotoxin binding sites indicate cholinergic synaptic interactions in the antennal lobe and a cholinergic pathway via a subset of olfactory projection neurons into the mushroom bodies [6].

Anatomical context of Ache

• All photoreceptor axons (short and long visual fibres) display AChE activity [7].
• However, AChE is also present in the proximal terminals of the visual fibres as well as in the intercellular spaces between visual fibre terminals and the postsynaptic neurones (monopolar cells) [7].
• Selective solubilization by melittin of glycophorin A and acetylcholinesterase from human erythrocyte ghosts [8].

Associations of Ache with chemical compounds

• Because acetylcholinesterase (AChE) hydrolyzes acetylcholine, a major neurotransmitter associated with learning in the insect brain, we searched for changes in AChE expression in the brain during bee behavioral development [4].
• In addition, treatment with the AChE-inhibitor metrifonate improved performance in an olfactory-learning assay [4].
• A difference in acetylcholinesterase sensitivity towards pirimicarb was also observed between foraging and emerging bees [5].
• Purified acetylcholinesterase (AChE) from electric eel (Electrophorus electricus) and carboxylesterases from a homogenate of honeybee heads (Apis mellifera) were used as esterases, each having different affinities for the substrates S-acetylthiocholine-iodide (ATC) and N-methylindoxylacetate (MIA) [9].
• The kinetic analysis of honeybee's acetylcholinesterase inhibition by fenitrothion, indicated that this insecticide acts (P< 0.05) on acetylcholinesterase activity [1].

Physical interactions of Ache

• We suggest that melittin binds to the hydrophobic site of acetylcholinesterase which anchors it in the lipid bilayer [8].

Analytical, diagnostic and therapeutic context of Ache

• Apiculture is an important source of Greek income and as the detection of anticholinesterase insecticides in bees is very difficult, investigation of the cause of death of honeybees due to acetylcholinesterase inhibition is of great value and will contribute to the differential diagnosis of bee diseases [10].

References