Articles by Sarah R. Nathan in JoVE
Synthesis and Evaluation of a Ruthenium-based Mitochondrial Calcium Uptake Inhibitor Sarah R. Nathan1, Justin J. Wilson1 1Department of Chemistry and Chemical Biology, Cornell University A protocol for the synthesis, purification, and characterization of a ruthenium-based inhibitor of mitochondrial calcium uptake is presented. A procedure to evaluate its efficacy in permeabilized mammalian cells is demonstrated.
Other articles by Sarah R. Nathan on PubMed
Synthetic Methods for the Preparation of a Functional Analogue of Ru360, a Potent Inhibitor of Mitochondrial Calcium Uptake Inorganic Chemistry. Mar, 2017 | Pubmed ID: 28244741 The mixed-valent oxo-bridged ruthenium complex [(HCO2)(NH3)4Ru(μ-O)Ru(NH3)4(O2CH)](3+), known as Ru360, is a selective inhibitor of mitochondrial calcium uptake. Although this compound is useful for studying the role of mitochondrial calcium in biological processes, its widespread availability is limited because of challenges in purification and characterization. Here, we describe our investigations of three different synthetic methods for the preparation of a functional analogue of this valuable compound. We demonstrate that this analogue, isolated from our procedures, exhibits potent mitochondrial calcium uptake inhibitory properties in permeabilized HeLa cells and in isolated mitochondria.
Microsecond Photocapacitance Transients Observed Using a Charged Microcantilever As a Gated Mechanical Integrator Science Advances. Jun, 2017 | Pubmed ID: 28691085 How light is converted to electricity in blends of organic donor and acceptor molecules is an unsettled question, partly because the spatial heterogeneity present in these blends makes them challenging to characterize. Although scanned-probe measurements have provided crucially important microscopic insights into charge generation and transport in these blends, achieving the subnanosecond time resolution needed to directly observe the fate of photogenerated charges has proven difficult. We use a charged microcantilever as a gated mechanical integrator to record photocapacitance indirectly by measuring the accumulated change in cantilever phase as a function of the time delay between precisely synchronized voltage and light pulses. In contrast with previous time-resolved scanned-probe photocapacitance measurements, the time resolution of this method is set by the rise and fall time of the voltage and light pulses and not by the inverse detection bandwidth. We demonstrate in an organic donor-acceptor blend the ability of this indirect, "phase-kick" technique to record multiexponential photocapacitance transients on time scales ranging from 40 μs to 10 ms. The technique's ability to measure subcycle, nanosecond charge dynamics is demonstrated by measuring the tens of nanosecond sample electrical charging time.
Dinuclear Nitrido-bridged Ruthenium Complexes Bearing Diimine Ligands Dalton Transactions (Cambridge, England : 2003). Oct, 2017 | Pubmed ID: 28994442 Reactions of K3[Ru2NCl8(H2O)2] with 2,2'-bipyridine (bpy), 4,4'-dimethyl-2,2'-bipyridine (dmbpy), and 4,4'-dimethoxy-2,2'-bipyridine (dmobpy) yielded the nitrido-bridged dinuclear complexes [Ru2N(L)2Cl5(DMF)] where L = bpy (1), dmbpy (2), and dmobpy (3). The crystal structures of these complexes reveal a linear Ru-N-Ru moiety with each ruthenium center bearing a bidentate diimine ligand. The complexes were further characterized by NMR, IR, and UV-vis spectroscopic methods and cyclic voltammetry. Because the compounds bear some structural similarities with the mitochondrial calcium uptake inhibitor Ru360, the ability of these complexes to act in this capacity was evaluated. The results demonstrate that 1-3 all fail to block mitochondrial calcium uptake, revealing new facets of the structure-activity relationships for ruthenium-based mitochondrial calcium uptake inhibitors.