Assessing the Mitochondrial Membrane Potential in Cells and In Vivo using Targeted Click Chemistry and Mass Spectrometry

• Published in: Cell metabolism Vol. 23; no. 2; pp. 379 - 385
• Main Authors: Logan, Angela, Pell, Victoria R., Shaffer, Karl J., Evans, Cameron, Stanley, Nathan J., Robb, Ellen L., Prime, Tracy A., Chouchani, Edward T., Cochemé, Helena M., Fearnley, Ian M., Vidoni, Sara, James, Andrew M., Porteous, Carolyn M., Partridge, Linda, Krieg, Thomas, Smith, Robin A.J., Murphy, Michael P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.02.2016; Cell Press
• Subjects: Animals; Cell Line; Click Chemistry - methods; Membrane Potential, Mitochondrial; Mice, Inbred C57BL; Molecular Probes - metabolism; Resource; Tandem Mass Spectrometry - methods
• ISSN: 1550-4131; 1932-7420
• DOI: 10.1016/j.cmet.2015.11.014

The mitochondrial membrane potential (Δψm) is a major determinant and indicator of cell fate, but it is not possible to assess small changes in Δψm within cells or in vivo. To overcome this, we developed an approach that utilizes two mitochondria-targeted probes each containing a triphenylphosphonium (TPP) lipophilic cation that drives their accumulation in response to Δψm and the plasma membrane potential (Δψp). One probe contains an azido moiety and the other a cyclooctyne, which react together in a concentration-dependent manner by “click” chemistry to form MitoClick. As the mitochondrial accumulation of both probes depends exponentially on Δψm and Δψp, the rate of MitoClick formation is exquisitely sensitive to small changes in these potentials. MitoClick accumulation can then be quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This approach enables assessment of subtle changes in membrane potentials within cells and in the mouse heart in vivo. [Display omitted] •Mass spectrometry and click chemistry can assess mitochondrial membrane potential•This approach can be applied to investigate membrane potential in cells and in vivo•Hypotheses dependent on small changes in membrane potential can be tested The mitochondrial membrane potential is central to the organelle’s many functions. Combining mitochondria targeted probes, click chemistry, and mass spectrometry, Logan et al. develop a highly sensitive approach to assess small changes in membrane potential in cells and in vivo, and show its utility in proof-of-principle experiments.