FIG 4.

The [Fe-S] cluster of the AldGH subcomplex is reduced by acetaldehyde. (A) SDS-PAGE of fraction 19 from Superdex 200 gel filtration chromatography of the AldGH subcomplex. Thirty micrograms of protein was separated by SDS-PAGE, followed by staining with Coomassie brilliant blue R-250. (B) Absorption spectrum from 250 to 700 nm of as-purified fraction 19 (0.55 mg protein mL⁻¹). The inset shows the absorption spectrum from 450 to 650 nm of as-purified fraction 19 (2.2 mg protein mL⁻¹) (black line). Potassium ferricyanide was added to a final concentration of 0.5 mM (blue line). Next, acetaldehyde was added to a final concentration of 1 mM (red line).