Open AccessRedox state and activity of molybdopterin cytosine dinucleotide (MCD) of CO dehydrogenase from Hydrogenophaga pseudoflava
Author(s) -
Tachil Jörg,
Meyer Ortwin
Publication year - 1997
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1997.tb10289.x
Subject(s) - chemistry , redox , oxidation state , flavoprotein , dehydrogenase , photochemistry , stereochemistry , biochemistry , enzyme , inorganic chemistry , catalysis
The redox state of molybdopterin cytosine dinucleotide (MCD) from the molybdo‐iron‐sulfur‐flavoprotein CO dehydrogenase of the carboxidotrophic bacterium Hydrogenophaga pseudoflava has been studied. MCD has been purified as the dicarboxamidomethylated derivative (5,6‐dihydro‐di(cam)MCD) under conditions maintaining the native redox state. The full oxidation of di(cam)MCD released two electrons per molecule and revealed no intermediate. Apparently, MCD occurs in air‐oxidized CO dehydrogenase in a redox state which is reduced by two electrons compared to the fully oxidized state. Due to the presence of 5′‐cytidine monophosphate (5′‐CMP) as a structural element, reduced di(cam)MCD (62 min half‐life) was twice as stable towards air oxidation as reduced di(carboxamidomethyl)molybdopterin (di(cam)MPT) (36 min half‐life).