Figure 4: In-gel Activities of Supercomplex-associated and Free Electron Transport Complexes in Subsarcolemmal Mitochondria

(A) Representative lanes from blue native polyacrylamide gel electrophoresis gels from failing hearts with in-gel activity stains for electron transport complexes CIV, CI, CV, and CII either free or in the supercomplex with arrows/brackets showing quantifiable bands on each gel. The 4 lanes represent 2 samples with untreated or elamipretide-treated mitochondria. (B and C) Supercomplex CIV activity is unchanged in untreated failing samples, but free CIV is decreased. (D to G) Elamipretide treatment of nonfailing samples had no effect on CIV activity (D, E) but in failing hearts improves (F) supercomplex-associated CIV but (G) not free CIV. Untreated hearts in (D to G) are shown with closed circles and treated hearts with open circles. NF, n = 19; HF, n = 21. AUC = area under the curve; Elam = elamipretide treated; Untr = untreated; other abbreviations as in Figure 1.