Purification of a novel coenzyme F420-dependent glucose-6-phosphate dehydrogenase from Mycobacterium smegmatis.
A variety of Mycobacterium species contained the 5-deazaflavin coenzyme known as F420. Mycobacterium smegmatis was found to have a glucose-6-phosphate dehydrogenase that was dependent on F420 as an electron acceptor and which did not utilize NAD or NADP. The enzyme was purified by ammonium sulfate fractionation, phenyl-Sepharose column chromatography, F420-ether-linked aminohexyl-Sepharose 4B affinity chromatography, and quaternary aminoethyl-Sephadex column chromatography, and the sequence of the first 26 N-terminal amino acids has been determined. The response of enzyme activity to a range of pHs revealed a two-peak pattern, with maxima at pH 5.5 and 8.0. The apparent Km values for F420 and glucose-6-phosphate were, respectively, 0.004 and 1.6 mM. The apparent native and subunit molecular masses were 78,000 and approximately 40,000 Da, respectively.
Purwantini
E
E
Department of Microbiology, University of Iowa, Iowa City 52242, USA.
Daniels
L
L
D005954:Glucosephosphate Dehydrogenase / Q000302:isolation & purification* / Q000378:metabolism; D007527:Isoenzymes / Q000302:isolation & purification / Q000378:metabolism; D009161:Mycobacterium / Q000737:chemistry / Q000201:enzymology*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D013045:Species Specificity
D007527:Isoenzymes; D009249:NADP; C015084:coenzyme F420; D005954:Glucosephosphate Dehydrogenase; D012256:Riboflavin