Single step purification of methylenetetrahydromethanopterin reductase from Methanobacterium thermoautotrophicum by specific binding to blue sepharose CL-6B.

Methylenetetrahydromethanopterin reductase from metanogenic archaebacteria catalyzes the reversible reduction of N5,N10-methylenetetrahydromethanopterin to N5-methyltetrahydromethanopterin with reduced coenzyme F420 as electron donor. The enzyme is involved in methane formation from CO2 and in methanol disproportionation to CO2 and CH4. We report here that the reductase from Methanobacterium thermoautotrophicum specifically binds to Blue Sepharose CL-6B. Binding was competitive with coenzyme F420 rather than with NAD, NADP, FAD, FMN, AMP, ADP and ATP. The reductase could also be desorbed with salt. Based on this property an affinity chromatographic procedure for the purification of the enzyme was developed.