Table 2. Genetic and biochemical studies on the mitochondrial ATP synthase coupling capacity.
Cells or mitochondria from wild type (wt) and mutant cells, as indicated (column 1), were studied. The percentage of petite strains as the homozygous haploid (column 2) or heterozygous diploid (column 3) is shown. The mean of the fluorescence intensity of the cells stained with Rhodamine 123 (column 4), the respiration using NADH as the substrate in the absence of ADP (State 4) and the presence of the uncoupler, FCCP (columns 5 and 6), the RCR, (column 7), the velocity of ATP hydrolysis using saturang ATP:Mg in the absence and presence of 5 μg of oligomycin with the associated oligomycin sensitivity (columns 8–10), and the measurement of the membrane potential using ethanol and ATP to generate the potential (columns 11 and 12) are shown. In each case, two to three independent experiments (n) were preformed and the SE displayed. All methods are detailed under “Experimental Procedures.” The abbreviations are: ND, not determined; NA, not applicable.
| Strains | Petite (Percent, n=3) | Petite Diploid (Percent, n=3) | Rhodamine 123 Vital Staining (Percent Wild Type, n=2) | Respiration μmoles O/min/mg protein (n=2) | RCR | ATPase μmoles/min/mg protein (n=2) | Oligomycin inhibition (Percent, n=2) | Fluorescence Quenching Rhodaminel23 (n=2) | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
| State 4 | FCCP | +Oligo. | ETOH | ATP | |||||||
| WT | 3±2 | <1 | 100 | 0.53 ± 0.06 | 1.62 ± 0.11 | 3.1±0.1 | 2.6±0.2 | 0.11±0.01 | 96±1 | 52±2 | 25±3 |
| αN67I | 15±3 | 7±3 | 64±11 | 0.75 ± 0.05 | 1.59 ± 0.16 | 2.1±0.2 | 2.0±0.2 | 0.44±0.03 | 78±1 | 40±3 | 16±2 |
| αF405S | 39±2 | 6±3 | 66±10 | 0.75 ± 0.16 | 1.41 ± 0.37 | 1.9±0.5 | 1.4±0.3 | 0.53±0.05 | 62±2 | 39±3 | 10±1 |
| αA295V | 44±14 | 8±2 | 12±2 | 0.04±0.01 | 0.05±0.01 | 1.3+0.1 | 0.7±0.1 | 0.52±0.04 | 26±2 | 4±2 | 5±3 |
| βR408G | 33±3 | 1±1 | 56±5 | 0.87 ± 0.09 | 1.46 ± 0.21 | 1.7±0.2 | 1.4±0.2 | 0.51±0.11 | 64±4 | 38±3 | 13±2 |
| βR408I | 34±8 | 6±3 | 20±1 | 0.52 ± 0.09 | 0.80 ± 0.06 | 1.5±0.2 | 1.5±0.2 | 0.75±0.02 | 50±1 | 34±5 | 14±3 |
| βV279F | 39±4 | 6±3 | 36±4 | 0.80± 0.03 | 1.37 ± 0.02 | 1.7±0.1 | 1.9±0.3 | 0.82±0.02 | 57±1 | 42±3 | 16+3 |
| γI270T | 24±1 | 3±1 | 49±2 | 0.88± 0.06 | 1.85 ± 0.22 | 2.1±03 | 2.1±0.1 | 0.29±0.04 | 86±4 | 37±5 | 18±1 |
| γT264A | 21±1 | 7±1 | 22±5 | 0.11±0.02 | 0.15±0.02 | 1.4±0.1 | 0.9±0.1 | 0.53±0.02 | 41±4 | 9±1 | 5±1 |
| Petite | NA | NA | 2±0 | ND | ND | NA | 0.7±0.1 | 0.54±0.05 | 24±1 | ND | ND |