Membrane-associated NADH dehydrogenase activities in Rhodobacter capsulatus: purification of a dihydrolipoyl dehydrogenase.
Berks BC., McEwan AG., Ferguson SJ.
The presence of several NADH dehydrogenase activities associated with cytoplasmic membrane vesicles of chemoheterotrophically grown Rhodobacter capsulatus MT1131 was demonstrated by combining isoelectric focusing with NADH-tetranitrobluetetrazolium activity staining, a procedure that should have general applicability in the analysis of bacterial NADH dehydrogenase activities. Low pI (pI = 5.7), Mid pI (pI = 6.9) and High pI (pI = 8.5) bands were resolved. The Mid pI NADH dehydrogenase activity was purified and identified as a dihydrolipoyl dehydrogenase. Our data indicate that this dihydrolipoyl dehydrogenase is derived from a 2-oxoacid dehydrogenase complex which is associated with the cytoplasmic membrane.