No / The human epidermis holds an autocrine acetylcholine production and degradation including functioning membrane integrated and cytosolic butyrylcholinesterase (BuchE). Here we show that BuchE activities increase 9-fold in the presence of calcium (0.5 × 10-3 M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. 45Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H2O2-mediated oxidation. Moreover, we confirmed the faster hydrolysis by calcium-activated BuchE using the neurotoxic organophosphate O-ethyl-O-(4-nitrophenyl)-phenylphosphonothioate (EPN). Considering the large size of the human skin with 1.8 m2 surface area with its calcium gradient in the 10¿3 M range, our results implicate calcium-activated BuchE as a major protective mechanism against suicide inhibition of AchE by organophosphates in this non-neuronal tissue
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/2691 |
| Date | January 2007 |
| Creators | Schallreuter, Karin U., Gibbons, Nick C., Elwary, Souna M.A., Parkin, Susan M., Wood, John M. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, No full-text in the repository |
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