Chlordecone interaction of calmodulin binding with phosphodiesterase.
The effects of organochlorine (O.C.) compounds, such as aldrin, dieldrin, endrin, isodrin, chlordecone and mirex, on calmodulin (CaM) activity were investigated. Changes induced by O.C. compounds on biological and physical properties of CaM were monitored in terms of phosphodiesterase stimulation and tyrosine fluorescence, respectively. None of the O.C. compounds altered tyrosine fluorescence of CaM in the presence of Ca2+. Except for chlordecone, none of the O.C. compounds inhibited CaM-activated phosphodiesterase (PDE). Chlordecone significantly decreased (P less than 0.05) CaM-activated PDE in a concentration-dependent manner without affecting the basal enzyme. Combination of chlordecone with W-7 (CaM antagonist) increased the inhibitory effect of W-7 on CaM activity. These results suggest that O.C. compounds may not be changing the tyrosine fluorescence of CaM. Among the O.C. compounds tested, chlordecone is a specific inhibitor of CaM-activated PDE.
Department of Neurology, University of Mississippi School of Medicine, Jackson 39216.
P J
PJ
Vig
D
D
Desaiah
B D
BD
Mehrotra
D001667:Binding, Competitive; D002147:Calmodulin / Q000378:metabolism*; D007631:Chlordecone / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence
D002147:Calmodulin; D007306:Insecticides; D010727:Phosphoric Diester Hydrolases; D007631:Chlordecone