The mechanism of inhibition by EDTA and EGTA of methanol oxidation by methylotrophic bacteria.
Ethyleneglycol (aminoethylether) tetra-acetic acid (EGTA) was shown to be a potent competitive inhibitor of electron transfer between methanol dehydrogenase (MDH) and its electron acceptor cytochrome cL. Addition of Ca2+ ions relieved the inhibition by removal of the inhibitory EGTA. Removal of EGTA by gel filtration completely relieved the inhibition. EGTA did not remove the tightly bound Ca2+ present in the MDH. Indo-1, a fluorescent analogue of EGTA, bound tightly to MDH in a 1:1 ratio but not to cytochrome cL; binding was prevented by EGTA. It was concluded that EGTA inhibits methanol oxidation by binding to lysyl or arginyl residues on MDH thus preventing docking with cytochrome cL.
Chan
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SERC Centre for Molecular Recognition, Department of Biochemistry, University of Southampton, UK.
Anthony
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D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism; D001120:Arginine / Q000378:metabolism; D001419:Bacteria / Q000187:drug effects* / Q000378:metabolism; D001665:Binding Sites; D003574:Cytochrome c Group / Q000378:metabolism; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D004533:Egtazic Acid / Q000378:metabolism / Q000494:pharmacology*; D005456:Fluorescent Dyes / Q000378:metabolism / Q000494:pharmacology; D007211:Indoles / Q000378:metabolism / Q000494:pharmacology; D008239:Lysine / Q000378:metabolism; D000432:Methanol / Q000378:metabolism*; D010084:Oxidation-Reduction
D003574:Cytochrome c Group; D005456:Fluorescent Dyes; D007211:Indoles; D004533:Egtazic Acid; D001120:Arginine; D004492:Edetic Acid; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D008239:Lysine; C048960:indo-1; D000432:Methanol