TY  - JOUR
PY  - 2007//
TI  - Calcium-activated butyrylcholinesterase in human skin protects acetylcholinesterase against suicide inhibition by neurotoxic organophosphates
JO  - Biochemical and biophysical research communications
A1  - Schallreuter, Karin U.
A1  - Gibbons, Nicholas C. J.
A1  - Elwary, Souna M.
A1  - Parkin, Susan M.
A1  - Wood, John M.
SP  - 1069
EP  - 1074
VL  - 355
IS  - 4
N2  - 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 (0.5x10(-3)M) via a specific EF-hand calcium binding site, whereas acetylcholinesterase (AchE) is not affected. (45)Calcium labelling and computer simulation confirmed the presence of one EF-hand binding site per subunit which is disrupted by H(2)O(2)-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 1.8m(2) 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.<p /> <p>Language: en</p>
LA  - en
SN  - 0006-291X
UR  - http://dx.doi.org/10.1016/j.bbrc.2007.02.078
ID  - ref1
ER  -