FIG. 1.
Identification of proteins in NDH-1 and modification of subunit NuoH with [14C]DCCD. Panel A shows the SDS-PAGE of NDH-1 (100 μg) after Source 15Q chromatography (lane 1) and the 2-butanol extract from 2 mg NDH-1 (lane 2). The gels were stained with Coomassie. Polypeptides were identified by mass spectroscopy (see Table 1 for results) or N-terminal sequencing (indicated with an asterisk). Nuo and Atp denote subunits of NDH-1 and the F1Fo ATPase, respectively. Panel B shows the autoradiograms of NDH-1 after modification with [14C]DCCD and separation by SDS-PAGE. Two aliquots of NDH-1 (30 μg each) were mixed with [14C]DCCD in the presence of 0.6 mM Na+ (lane 3) or 50 mM Na+ (lane 4). Lane 5 shows the autoradiogram of the 2-butanol extract from 2 mg NDH-1 after modification with [14C]DCCD in the presence of 0.6 mM Na+.