Purification and properties of the 5,10-methenyltetrahydromethanopterin cyclohydrolase from Methanobacterium thermoautotrophicum.
AUTOR(ES)
DiMarco, A A
RESUMO
The 5,10-methenyltetrahydromethanopterin cyclohydrolase of Methanobacterium thermoautotrophicum was purified 128-fold to homogeneity. The enzyme had a subunit Mr of 41,000 as indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. From high-performance size exclusion chromatography of the native protein, an Mr of 82,000 was determined, suggesting a dimer of identical subunits. The enzyme was inhibited by 10-formyltetrahydromethanopterin and stimulated by Mg2+. Evaluation of the reaction equilibrium indicated that the methenyl derivative was favored over 5-formyltetrahydromethanopterin, with a much higher equilibrium constant than for the analogous reaction of tetrahydrofolate derivatives. Folate derivatives did not serve as substrates for this enzyme.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=213648Documentos Relacionados
- Purification and properties of 5,10-methenyltetrahydromethanopterin cyclohydrolase from Methanosarcina barkeri.
- Purification and characterization of an anabolic fumarate reductase from Methanobacterium thermoautotrophicum.
- 5-Fluorouracil-resistant strain of Methanobacterium thermoautotrophicum.
- Purification and use of Methanobacterium wolfei pseudomurein endopeptidase for lysis of Methanobacterium thermoautotrophicum.
- ATP activation and properties of the methyl coenzyme M reductase system in Methanobacterium thermoautotrophicum.
