BN-PAGE electrophoresis of C. albicans CRC complex proteins in WT, GOA31 (goa1Δ/goa1Δ), and GOA32 (GOA1/goa1Δ) cells. (A) Coomassie stain of purified proteins of CI to CIV. Equal concentrations of total mitochondrial proteins from all strains were separated by BN-PAGE and stained accordingly. CI is significantly reduced in GOA31 compared to levels in the matched set of control strains, WT and GOA32. The molecular markers indicated on the left side are NativeMark (unstained protein standard; Invitrogen). (B) The in-gel enzyme activity of CI in BN-PAGE was assayed within 60 min after incubating the gel in reaction medium (0.1 M Tris-HCl, pH 7.4, 0.2 mM NADH as a substrate, and 0.2% NBT). Less CI enzyme activity in the GOA31 (goa1Δ/goa1Δ) strain was observed with NBT than in the WT and GOA32 (GOA1/goa1Δ) strains.