- Investigation of the mechanism of action of pyrogallol-phloroglucinol transhydroxylase by using putative intermediates
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Pyrogallol-phloroglucinol transhydroxylase from Pelobacter acidigallici, a molybdopterin-containing enzyme, catalyzes a key reaction in the anaerobic degradation of aromatic compounds. In vitro, the enzymatic reaction requires 1,2,3,5-tetrahydroxy-benzene as a cocatalyst and the trans-hydroxylation occurs without exchange with hydroxy groups from water. To test our previous proposal that the transfer of the hydroxy group occurs via 2,4,6,3′,4′, 5′-hexahydroxydiphenyl ether as an intermediate, we synthesized this compound and investigated its properties. We also describe the synthesis and characterization of 3,4,5,3′,4′,5′-hexahydroxydiphenyl ether. Both compounds could substitute for the cocatalyst in vitro. This indicates that the diphenyl ethers can intrude into the active site and initiate the catalytic cycle. Recently, the X-ray crystal structure of the transhydroxylase (TH) was published[16] and it supports the proposed mechanism of hydroxy-group transfer.
- Paizs, Csaba,Bartlewski-Hof, Ulrike,Rétey, János
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p. 2805 - 2811
(2008/02/05)
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