Activation of the methylreductase system from Methanobacterium bryantii by Corrins
Corrins activated the methylreductase system from Methanobacterium bryantii three- to fivefold in extracts resolved from low-molecular-weight factors. Corrins did not substitute for ATP and component B, which were also required for maximal activity. The concentration of diaquacobinamides required for one-half maximal activity was 1 ..mu..M. The concentrations of cyanocobalamin, methylcobalamin, Co..cap alpha..-(5-hydroxybenzimidazoyl)-Co..beta..-cyanocobamide, and 5'-deoxyadenosylcobinamide required for one-half maximal activity were between 4 and 7 ..mu..M. Deoxyadenosylcobalamin was nearly inactive. Activation was independent of thiols, coenzyme M, and ATP. Corrins were required in catalytic concentrations, methylcobalamin was not required, and methanogenesis was enzymatic. Corrin activation of the methylreductase is a novel effect on methanogenesis. However, the physiological significance of the corrin activation is uncertain.
- Research Organization:
- Univ. of Illinois, Urbana
- OSTI ID:
- 5459788
- Journal Information:
- J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 164:1; ISSN JOBAA
- Country of Publication:
- United States
- Language:
- English
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