Fig. 2

ATP consumption by creatine kinases. 1 μM of each of the four purified isoforms of creatine kinase were incubated for 30 min with (ATP+/Cr+) or without (ATP−/Cr-) 50 μM of ATP and 5 mM of creatine. Luminescence was measured using red-luciferase and normalized by positive control (without creatine kinase, with 50 μM of ATP and 5 mM creatine). Standard deviation represent three independent experiments. Ø – without creatine kinase; CKB – brain creatine kinase; CKM – muscle creatine kinase; uMtCK – ubiquitous mitochondrial creatine kinase; sMtCK – sarcomeric mitochondrial creatine kinase