ISSN:
1432-072X
Keywords:
Methanobacterium thermoautotrophicum
;
Coenzyme M
;
7-Mercaptoheptanoylthreonine phosphate
;
5-Methyltetrahydromethanopterin: coenzyme M methyltransferase
;
Corrinoid enzyme
;
Reductive activation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The conversion of formaldehyde to methylcoenzyme M in cell-free extracts of Methanobacterium thermoautotrophicum was stimulated up to 10-fold by catalytic amounts of the heterodisulfide (CoM-S-S-HTP) of coenzyme M and 7-mercaptoheptanoylthreonine phosphate. The stimulation required the additional presence of ATP, also in catalytic concentrations. ATP and CoM-S-S-HTP were mutually stimulatory on the methylcoenzyme M formation and it was concluded that the compounds were both involved in the reductive activation of the methyltetrahydromethanopterin: coenzyme M methyltransferase. Micromolar concentrations of benzyl viologen or cyanocobalamin inhibited the formaldehyde conversion; these compounds, however, strongly stimulated the reduction of CoM-S-S-HTP. The results described here closely resemble observations made on the activation and reduction of CO2 to formylmethanofuran indicating that this step and the reductive activation of the methyltransferase are controlled by some common mechanism.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00423326