Figure 7.

Additional sites of KK174 photolabeling in E73Q mVDAC1. A, an MS1 doublet corresponding to the peptide TGKKNAKIKTGY labeled with KK174 (z = 4) and coupled to light and heavy FLI-tag. B, fragmentation (ETD) spectra corresponding to the heavy feature in A. Site defining ions localize KK174 labeling to Lys¹¹⁰. C, an MS1 doublet corresponding to the peptide AVGYKTDEF labeled with KK174 (z = 4) and coupled to light and heavy FLI-tag. D, fragmentation (ETD) spectra corresponding to the light feature in C. Site defining ions localize KK174 labeling to Tyr¹⁷³. E, mVDAC1 crystal structure (PDB code 3emn) highlighting the photolabeled residue Lys¹¹⁰. F, a cholesterol binding pose from Autodock located within a previously identified cholesterol binding pocket (8) formed by Val¹⁷¹, Ala¹⁵¹, Leu¹⁴⁴, Ile¹²³, Tyr¹⁴⁶, and Trp¹⁴⁹. The aliphatic tail of cholesterol in this pose is near Tyr¹⁷³, consistent with KK174 labeling of this residue in E73Q mVDAC1.