To determine the prevalence and identify any enrichment of lysine propionylation in PCC deficiency, an analysis comparing the propionylated liver proteins of control and liver-specific Pcca knockout mice was performed. Liver-specific knockout of PCC activity was induced in mice with floxed axons for the Pcca gene (Pcca ff) at 5 weeks of age using iCre-AAV with a TBG promoter. For controls, Pcca ff mice were injected with eGFP-AAV under the same promoter.