Fig. 2.

MALDI-TOF/MS of standard cardiolipin and cardiolipin extracted from cytochrome c oxidase or complex I. (A) MALDI-TOF mass spectra of standard cardiolipin. Beef heart standard cardiolipin was obtained from Avanti Polar Lipids. (B) MALDI-TOF mass spectra of HPLC-isolated cardiolipin extracted from HiTrapQ-purified cytochrome c oxidase. (C) MALDI-TOF mass spectra of HPLC-isolated cardiolipin extracted from complex I. In each case cardiolipin was dissolved in chloroform and ∼15 pmol/μL spotted on the MALDI target using dihydroxybenzoic acid as the matrix. Each spectrum represents an average of 100 laser shots. Observed major peaks correspond to tetra-linoleoyl cardiolipin (1448 ± 1) modified by sodium ions.