Fig 2: Myofilament phosphorylation and contractile properties. (A) ProQ phosphorylation analysis and Coomassie staining of cardiac myofilament proteins after IR. (B) Phosphorylation levels of MyBP-C, desmin, cTnT, and cTnI. n = 7–8 mice per group. (C–E) Representative Western blots of cTnI phosphorylation (C) and quantification of cTnI phosphorylation at Ser23/24 (D) and Ser43 (E). n = 5–6 mice per group. (F) Illustrations of actomyosin MgATPase activity in each group. (G) Myofilament EC50 values (indicators of myofilament calcium sensitivity). (H) Maximum actomyosin MgATPase activity. n = 7 mice per group. All data are presented as the mean ± SEM; *P < 0.05 between the groups (two-way ANOVA, Tukey’s multiple comparisons test).