1. Existence of two membrane-bound acetylcholinesterases in the honey bee head
- Author
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Luc P. Belzunces, Jean-Luc Brunet, Alexandra Badiou, Unité mixte de recherche Ecologie des invertébrés (UAPV), and Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU)
- Subjects
Physiology ,[SDV]Life Sciences [q-bio] ,HYMENOPTERA ,APIFORMES ,Biochemistry ,HONEYBEE ,chemistry.chemical_compound ,TETE ,Phosphoinositide Phospholipase C ,0302 clinical medicine ,INSECTE SOCIAL ,0303 health sciences ,Ion exchange ,Chemistry ,General Medicine ,Bees ,Chromatography, Ion Exchange ,Acetylcholinesterase ,Membrane ,language ,Insect Proteins ,Electrophoresis, Polyacrylamide Gel ,APIDAE ,POLLINISATEUR ,Octoxynol ,Aché ,ETAT CONFORMATIONNEL ,SOCIAL INSECT ,03 medical and health sciences ,Affinity chromatography ,Animals ,030304 developmental biology ,CONFORMATIONAL STATE ,Chromatography ,Phospholipase C ,Elution ,APIS MELLIFERA ,Membrane Proteins ,FORME MEMBRANNAIRE ,language.human_language ,ABEILLE DOMESTIQUE ,Membrane protein ,MOLECULAR FORM ,Insect Science ,SPECIFIC AGGREGATION ,POLLINATOR ,AGREGATION ,Head ,030217 neurology & neurosurgery - Abstract
International audience; Two acetylcholinesterase (EC 3.1.1.7) membrane forms AChEm1 and AChEm2, have been characterised in the honey bee head. They can be differentiated by their ionic properties: AChEm1 is eluted at 220 mM NaCl whereas AChEm2 is eluted at 350 mM NaCl in anion exchange chromatography. They also present different thermal stabilities. Previous processing such as sedimentation, phase separation, and extraction procedures do not affect the presence of the two forms. Unlike AChEm1, AChEm2 presents reversible chromatographic elution properties, with a shift between 350 to 220 mM NaCl, depending on detergent conditions. Purification by affinity chromatography does not abolish the shift of the AChEm2 elution. The similar chromatographic behaviour of soluble AChE strongly suggests that the occurrence of the two membrane forms is not due to the membrane anchor. The two forms have similar sensitivities to eserine and BW284C51. They exhibit similar electrophoretic mobilities and present molecular masses of 66 kDa in SDS-PAGE and a sensitivity to phosphatidylinositol-specific phospholipase C in non-denaturing conditions, thus revealing the presence of a glycosyl-phosphatidylinositol anchor. We assume that bee AChE occurs in two distinct conformational states whose AChEm2 apparent state is reversibly modulated by the Triton X-100 detergent into AChEm1
- Published
- 2007
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