Proteomic analysis reveals that lysine acetylation mediates the effect of antemortem stress on postmortem meat quality development

•Acetylome was analyzed in postmortem muscle with or without antemortem stress.•Acetylproteins enriched in contraction, metabolism, apoptosis, and Ca2+ signaling.•Antemortem stress regulated postmortem glycolysis via acetylation/deacetylation.•Preslaughter handling regulated rigor mortis via acetylation/deacetylation.•Antemortem stress regulated apoptosis via acetylation/deacetylation. To explore the involvement of protein lysine acetylation in the conversion of muscle to meat, a quantitative analysis of the acetylome in postmortem porcine muscle with or without antemortem stress was conducted. In total, 771 acetylpeptides containing 681 lysine acetylation sites mapping to 176 acetylproteins were identified. Acetylproteins were enriched in muscle contraction, carbohydrate metabolism, cell apoptosis and calcium signaling. Bioinformatic analysis suggests that preslaughter handling may be associated with glycolysis in postmortem muscle and the overall meat quality, via acetylation of multiple enzymes of glycogenolysis/glycolysis, regulate rigor mortis via acetylation of contractile, ATP production and calcium signaling-related proteins, and regulate stress response, cell apoptosis and meat tenderization via regulating the functions of heat shock proteins and permeability transition pore complex. This study provides the first overview of the acetylome in postmortem muscle as affected by preslaughter handling and broadens knowledge of the biochemistry regulating meat quality development.