Purification and properties of 5,10-methylenetetrahydromethanopterin dehydrogenase and 5,10-methylenetetrahydromethanopterin reductase, two coenzyme F420-dependent enzymes, from Methanosarcina barkeri.
Biochim Biophys Acta
; 1079(3): 293-302, 1991 Sep 20.
Article
em En
| MEDLINE
| ID: mdl-1911853
ABSTRACT
5,10-Methylenetetrahydromethanopterin dehydrogenase and 5,10-methylenetetrahydromethanopterin reductase have been purified to homogeneity by a factor of 86 and 68, respectively, from methanol-grown Methanosarcina barkeri cells. The dehydrogenase was isolated as a hexamer of a single 35 kDa subunit, whereas the reductase was composed of four identical 38 kDa subunits. The purified oxygen-stable enzymes catalyzed the oxidation of 5,10-methylenetetrahydromethanopterin and methyltetrahydromethanopterin with Vmax values of 3000 and 200 mumol min-1 mg-1, respectively. The methanogenic electron carrier coenzyme F420 was a specific electron acceptor for both enzymes. Steady state kinetics for the two enzymes were in agreement with ternary complex (sequential) mechanisms. Methylene reductase and methylene dehydrogenase are proposed to function in the methanol oxidation step to CO2.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Riboflavina
/
Methanosarcina barkeri
/
Oxirredutases atuantes sobre Doadores de Grupo CH-NH
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
Holanda