Open AccessCharacterisation of a red form of methanol dehydrogenase from the marine methylotroph Methylophaga marina
Author(s) -
Chan H.T.C.,
Anthony C.
Publication year - 1992
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.1574-6968.1992.tb05478.x
Subject(s) - methanol dehydrogenase , methylotroph , tetramer , biochemistry , cytochrome , enzyme , chemistry , cytochrome c , dehydrogenase , electron acceptor , biology , stereochemistry , mitochondrion
The quinoprotein methanol dehydrogenase (MDH) of the marine methylotroph Methylophaga marina is similar to that of other methylotrophs in being an α 2 β 2 tetramer containing two molecules of PQQ and a single atom of calcium. Its electron acceptor is cytochrome c L and interaction of the two proteins is by way of carboxylates on the cytochrome and lysyl residues on the α subunit of MDH. The reaction was not, however, sensitive to high ionic strength as was the reaction in non‐halophilic bacteria. A red form of the enzyme was sometimes produced which had a low specific activity and a low calcium content. Activity was restored by incubation with Ca 2+ which also produced the typical (green) enzyme, with a typical absorption spectrum. This provides the first demonstration of reconstitution of active MDH from enzyme lacking calcium isolated from a wild‐type methylotroph.