title: Assessing the Delivery of Molecules to the Mitochondrial Matrix Using Click Chemistry.
abstract: Mitochondria are central to health and disease, hence there is considerable interest in developing mitochondria-targeted therapies that require the delivery of peptides or nucleic acid oligomers. However, progress has been impeded by the lack of a measure of mitochondrial import of these molecules. Here, we address this need by quantitatively detecting molecules within the mitochondrial matrix. We used a mitochondria- targeted cyclooctyne (MitoOct) that accumulates several- hundredfold in the matrix, driven by the membrane potential. There, MitoOct reacts through click chemistry with an azide on the target molecule to form a diagnostic product that can be quantified by mass spectrometry. Because the membrane potential-dependent MitoOct concentration in the matrix is essential for conjugation, we can now determine definitively whether a putative mitochondrion-targeted molecule reaches the matrix. This "ClickIn" approach will facilitate development of mitochondria-targeted therapies.
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.|Medical Research Council Mitochondrial Biology Unit, Cambridge, UK.|The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Kurt
authors.initials: K
authors.lastname: Hoogewijs
authors.affiliation: Medical Research Council Mitochondrial Biology Unit, Cambridge, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: James
authors.affiliation: Department of Chemistry, University of Otago, Dunedin, New Zealand.
authors.forename: Robin A J
authors.initials: RA
authors.lastname: Smith
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK. mgait@mrc-lmb.cam.ac.uk.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gait
authors.affiliation: Medical Research Council Mitochondrial Biology Unit, Cambridge, UK. mpm@mrc-mbu.cam.ac.uk.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Murphy
authors.affiliation: The Wellcome Trust Centre for Mitochondrial Research, Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne, UK. robert.lightowlers@ncl.ac.uk.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Lightowlers
mesh_terms: D001386:Azides / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics; D057930:Click Chemistry / Q000379:methods*; D034242:Cyclooctanes / Q000737:chemistry / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D058990:Molecular Targeted Therapy / Q000379:methods
chemical_list: D001386:Azides; D034242:Cyclooctanes; D004337:Drug Carriers; C474479:cyclooctane
keywords: click chemistry; drug delivery; mitochondria; mitochondrial DNA; targeting