Tomás Gamasa, MaríaMartínez-Calvo, MiguelRodríguez Couceiro, JoséMascareñas Cid, José Luis2017-10-212017-10-212016-09-07Toma´s-Gamasa, M. et al. Transition metal catalysis in the mitochondria of living cells. Nat. Commun. 7:12538 doi: 10.1038/ncomms12538 (2016)http://hdl.handle.net/10347/16015The development of transition metal catalysts capable of promoting non-natural transformations within living cells can open significant new avenues in chemical and cell biology. Unfortunately, the complexity of the cell makes it extremely difficult to translate standard organometallic chemistry to living environments. Therefore, progress in this field has been very slow, and many challenges, including the possibility of localizing active metal catalysts into specific subcellular sites or organelles, remain to be addressed. Herein, we report a designed ruthenium complex that accumulates preferentially inside the mitochondria of mammalian cells, while keeping its ability to react with exogenous substrates in a bioorthogonal way. Importantly, we show that the subcellular catalytic activity can be used for the confined release of fluorophores, and even allows selective functional alterations in the mitochondria by the localized transformation of inert precursors into uncouplers of the membrane potential.eng© The Author(s) 2016. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/CatalysisChemical biologyOrganic chemistryjournal article10.1038/ncomms125382041-1723open access