Protein Modification by Endogenously Generated Lipid Electrophiles: Mitochondria as the Source and Target

Authors

Beavers WN William N , Rose KL Kristie L , Galligan JJ James J , Mitchener MM Michelle M , Rouzer CA Carol A , Tallman KA Keri A , Lamberson CR Connor R , Wang X Xiaojing , Hill S Salisha , Ivanova PT Pavlina T , Brown HA H Alex , Zhang B Bing , Porter NA Ned A , Marnett LJ Lawrence J .
ACS chemical biology. 2017 6 28; 12(8).
2062-2069

Abstract

Determining the impact of lipid electrophile-mediated protein damage that occurs during oxidative stress requires a comprehensive analysis of electrophile targets adducted under pathophysiological conditions. Incorporation of ω-alkynyl linoleic acid into the phospholipids of macrophages prior to activation by Kdo-lipid A, followed by protein extraction, click chemistry, and streptavidin affinity capture, enabled a systems-level survey of proteins adducted by lipid electrophiles generated endogenously during the inflammatory response. Results revealed a dramatic enrichment for membrane and mitochondrial proteins as targets for adduction. A marked decrease in adduction in the presence of MitoTEMPO demonstrated a primary role for mitochondrial superoxide in electrophile generation and indicated an important role for mitochondria as both a source and target of lipid electrophiles, a finding that has not been revealed by prior studies using exogenously provided electrophiles.