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Title: Purification and characterization of the reduced-nicotinamide-dependent 2,2 prime -dithiodiethanesulfonate reductase from Methanobacterium thermoautotrophicum. Delta. H

Journal Article · · Journal of Bacteriology; (USA)
OSTI ID:5948483

A novel reduced nicotinamide-dependent disulfide reductase, the 2,2{prime}-dithiodiethanesulfonate ((S-CoM){sub 2}) reductase (CoMDSR) of Methanobacterium thermoautotrophicum was purified 405-fold to electrophoretic homogeneity. Both NADPH and NADH functioned as electron donors, although rates with NADPH were three times higher. Reduced factor F{sub 420}, the deazaflavin electron carrier characteristic of methanogenic bacteria, was not a substrate for the enzyme. The enzyme was most active with (S-CoM){sub 2} but could also reduce L-cystine at 23% the (S-CoM){sub 2} rate. It may be involved in the redox balance of the cell, such as the NADPH-dependent bis-{gamma}-glutamylcystine reductase with which it shows physical similarity in another archaebacterium, Halobacterium halobium. The CoMDSR might also be involved in regenerating the coenzyme M trapped as its homodisulfide, a nonutilizable form of the cofactor.

OSTI ID:
5948483
Journal Information:
Journal of Bacteriology; (USA), Vol. 172:11; ISSN 0021-9193
Country of Publication:
United States
Language:
English