The candidate received his Ph.D. from the UC Berkeley, under the joint direction of Kenneth Raymond and Robert Bergman where he studied host-guest chemistry, molecular recognition, and catalysis in water-soluble supramolecular complexes. He is currently an NIH postdoctoral fellow in Stephen Lippard's laboratory at MIT working on developing fluorescent probes for nitric oxide. The candidate's research interests span the field of molecular recognition with a specific focus on how microscopic processes lead to the recognition of individual atoms, functional groups and molecules. The candidate will use his background in mechanistic studies and molecular recognition to pursue his research interests as a principle investigator. His independent research will focus on the development of new tools for the detection and imaging of small molecules in biology. Nitric oxide (NO) and hydrogen sulfide (H2S) are now accepted as biologically important gaseous transmitters. Both NO and H2S are produced endogenously and are finely regulated by the body. Nitric oxide is beneficial for vasodilation and immune activity at low cellular concentrations but overproduction can lead to the proliferation of reactive NO species that have been implicated in carcinogenesis and several degenerative neurological disorders, including Alzheimer's (AD), Parkinson's, and Huntington's disease, as well as multiple sclerosis. Similarly, H2S has been implicated in AD, Downs syndrome and other forms of metal deficiency. H2S also plays an active role in inflammation and in blood pressure regulation. Despite the recognized importance of both of these gaseous transmitters, the current methods for detection in live cells are limited. The postdoctoral phase of the proposed research will focus on the development of new NO-selective fluorescent probes that address current limitations of NO detection. Transition metal based NO binding sites will be used to develop probes that can reversibly bind NO and probes that emit in the NIR. The proposed family of fluorescent probes will use paramagnetic (S=1/2) metals serving the dual role as both fluorescence quencher and NO binding site. Coordination of NO will form a diamagnetic (S=0) complex and restore the fluorescence of the pendant fluorophore. Adsorption or covalent attachment of such complexes to solubilized single-walled carbon nanotubes (SWNTs) will be used to develop NO-selective probes that emit in the NIR. The independent research phase of the proposed research will investigate the design of H2S-selective fluorescent probes for the imaging of endogenously produced H2S. Currently, such H2S detection methods are lacking and most measurements rely on bulk tissue measurements. The new H2S-selective fluorescent probes for use in live cells will provide much needed tools for the study of the biological functions of H2S. The unique physical properties of H2S will all be exploited in the design of H2S-selective fluorescent probes. Fluorophores will be derivatized with specially designed protecting groups that can only be removed by H2S. Removal of the fluorophore protecting group will restore the fluorescence, thus forming a turn-on probe for H2S.
Both nitric oxide (NO) and hydrogen sulfide (H2S) have been identified as important endogenous gaseous transmitters in the human body and have been implicated in carcinogenesis, hypertension, and several neurological disorders including Alzheimer's disease, Parkinson's disease, Downs syndrome, and multiple sclerosis. Despite this interest, there are currently few methods to detect or image intracellular levels of these small molecule transmitters. This proposal presents the design of fluorescent probes for NO and H2S, which would allow for the selective detection and imaging of these endogenous gasses in live cells.
|Bailey, T Spencer; Donor, Micah T; Naughton, Sean P et al. (2015) A simple bioluminescent method for measuring D-amino acid oxidase activity. Chem Commun (Camb) 51:5425-8|
|Ghosh, Mitrajit; van den Akker, Nynke M S; Wijnands, Karolina A P et al. (2013) Specific visualization of nitric oxide in the vasculature with two-photon microscopy using a copper based fluorescent probe. PLoS One 8:e75331|
|Pluth, Michael D; Lippard, Stephen J (2012) Reversible binding of nitric oxide to an Fe(III) complex of a tetra-amido macrocycle. Chem Commun (Camb) 48:11981-3|
|Sartoretto, Juliano L; Kalwa, Hermann; Shiroto, Takashi et al. (2012) Role of Ca2+ in the control of H2O2-modulated phosphorylation pathways leading to eNOS activation in cardiac myocytes. PLoS One 7:e44627|
|Pluth, Michael D; Tomat, Elisa; Lippard, Stephen J (2011) Biochemistry of mobile zinc and nitric oxide revealed by fluorescent sensors. Annu Rev Biochem 80:333-55|
|Pluth, Michael D; Chan, Maria R; McQuade, Lindsey E et al. (2011) Seminaphthofluorescein-based fluorescent probes for imaging nitric oxide in live cells. Inorg Chem 50:9385-92|
|Sartoretto, Juliano L; Kalwa, Hermann; Pluth, Michael D et al. (2011) Hydrogen peroxide differentially modulates cardiac myocyte nitric oxide synthesis. Proc Natl Acad Sci U S A 108:15792-7|
|McQuade, Lindsey E; Pluth, Michael D; Lippard, Stephen J (2010) Mechanism of nitric oxide reactivity and fluorescence enhancement of the NO-specific probe CuFL1. Inorg Chem 49:8025-33|