The goal of the proposed program is to design and synthesize new emissive nucleoside and nucleotide analogs and implement them as probes for monitoring nucleoside- and nucleotide-based transformations as well as nucleic acids function, structure, dynamics and recognition. Advancing effective fluorescence-based tools for exploring nucleoside, nucleotide and oligonucleotides, as well as their metabolism, regulatory processes and interactions with potential therapeutic agents will further knowledge and advance new diagnostic approaches, facilitating drug discovery. Specifically, we will address:
AIM 1. To design, synthesize and incorporate new isomorphic fluorescent nucleoside and nucleotides. The main design criteria include: (i) High structural similarity to the native nucleobases to faithfully mimic their size and shape, as well as hybridization and recognition properties, (ii) Red shifted absorption spectrum to minimize overlap with the absorption of the natural bases, and (iii) Adequate emission quantum efficiency and visible emission wavelengths. Efficient synthetic and enzymatic pathways will be devised, providing the nucleosides, nucleotides and oligonucleotide.
AIM 2. To photophysically and biophysically characterize the modified nucleosides and oligonucleotides. The photophysical characteristics (e.g., absorption and emission maxima, quantum yield and brightness, excited state lifetime, as well as susceptibility to environmental polarity and static and dynamic quenching by native nucleosides) will be rigorously evaluated and interpreted. The outcome of these analyses and the data generated dictate the utility and potential applications of the nucleoside surrogates.
AIM 3. To implement the promising emissive analogs in biophysical, biochemical and discovery assays. These assays will facilitate: (i) Studying the enzymatic deamination of adenosine to inosine, which occurs in three key biological contexts: purine metabolism, mRNA editing and tRNA maturation; (ii) Investigating the enzymatic synthesis of emissive second messengers, such as c-di-NMPs, and their interactions with riboswitches and proteins (e.g., STING), (iii) Monitoring RNA?protein binding (e.g., k- turn/7LAe) and translational events, including programmed ribosomal frameshifting, which could be detrimental to native protein synthesis, but, when programmed (e.g., in viral replication) can maximize protein expression. Nucleic acids play central roles in cellular events and, as such, have immense impact on the emergence of diseases and, in turn, on human health. This necessitates the development of new effective tools for studying their recognition properties and alteration by exogenous agents. The emissive nucleoside analogs designed and prepared will be implemented in novel real time fluorescence-based assays. These investigations will further the fundamental understanding of key biological processes related to disease development and will have long-term impact on improving human health by advancing knowledge and facilitating drug discovery.

Public Health Relevance

Nucleic acids and their building blocks play central roles in all cellular events and, as such, have immense impact on the emergence of diseases and, in turn, on human health. The goal of the proposed program is to design, synthesize and implement new emissive nucleoside and nucleotide analogs as probes for nucleic acids function, structure, dynamics and recognition. Novel real-time fluorescence-based methods for exploring nucleic acids and their interactions with potential therapeutic agents will further the fundamental understanding of key biological processes related to disease development and will have long-term impact on improving human health by advancing diagnostic tools and facilitating drug discovery.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM069773-15
Application #
9690071
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
2004-01-01
Project End
2021-04-30
Budget Start
2019-05-01
Budget End
2020-04-30
Support Year
15
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California, San Diego
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Hallé, François; Fin, Andrea; Rovira, Alexander R et al. (2018) Emissive Synthetic Cofactors: Enzymatic Interconversions of tz A Analogues of ATP, NAD+ , NADH, NADP+ , and NADPH. Angew Chem Int Ed Engl 57:1087-1090
Rovira, Alexander R; Tor, Yitzhak (2018) Synthesis of unique spirocyclic orthoester-type derivatives of isothiazolo[4,3-d]pyrimidine nucleosides. J Antibiot (Tokyo) 71:342-344
Rovira, Alexander R; Fin, Andrea; Tor, Yitzhak (2017) Expanding a fluorescent RNA alphabet: synthesis, photophysics and utility of isothiazole-derived purine nucleoside surrogates. Chem Sci 8:2983-2993
Kilin, Vasyl; Gavvala, Krishna; Barthes, Nicolas P F et al. (2017) Dynamics of Methylated Cytosine Flipping by UHRF1. J Am Chem Soc 139:2520-2528
Rovira, Alexander R; Fin, Andrea; Tor, Yitzhak (2017) Emissive Synthetic Cofactors: An Isomorphic, Isofunctional, and Responsive NAD+ Analogue. J Am Chem Soc 139:15556-15559
Liu, Wei; Shin, Dongwon; Ng, Martin et al. (2017) Stringent Nucleotide Recognition by the Ribosome at the Middle Codon Position. Molecules 22:
Hopkins, Patrycja A; McCoy, Lisa S; Tor, Yitzhak (2017) Enzymatic incorporation and utilization of an emissive 6-azauridine. Org Biomol Chem 15:684-690
Li, Yao; Fin, Andrea; McCoy, Lisa et al. (2017) Polymerase-Mediated Site-Specific Incorporation of a Synthetic Fluorescent Isomorphic G Surrogate into RNA. Angew Chem Int Ed Engl 56:1303-1307
Vranken, C; Fin, A; Tufar, P et al. (2016) Chemoenzymatic synthesis and utilization of a SAM analog with an isomorphic nucleobase. Org Biomol Chem 14:6189-92
Freeman, Noam S; Moore, Curtis E; Wilhelmsson, L Marcus et al. (2016) Chromophoric Nucleoside Analogues: Synthesis and Characterization of 6-Aminouracil-Based Nucleodyes. J Org Chem 81:4530-9

Showing the most recent 10 out of 65 publications