The long term goals of this research include the development of methodology to permit the folding, flexibility and dynamics of protein structure to be interrogated, and the development and use of fluorescent probes in novel ways to enhance our understanding of protein structure, dynamics and function. During the five years of proposed research, the focus of efforts will be on study of the mechanism of modified DHFRs through steady state, pre-steady state and single molecule kinetic studies. Fluorescence spectroscopy will be used to study the protein conformational changes and their association with the key steps in DHFR catalysis.

Public Health Relevance

The present project is aimed at describing and quantifying the particular sequence, structural and dynamic properties that operate to enhance enzymatic catalysis. The proposed studies will provide important insights into enzyme function and will foster protein design and drug discovery efforts. The enzyme DHFR, which is the target of important antineoplastic and antimicrobial drugs, will be the focus of our efforts.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
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Macromolecular Structure and Function E Study Section (MSFE)
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Lewis, Catherine D
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Arizona State University-Tempe Campus
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Liu, C Tony; Layfield, Joshua P; Stewart 3rd, Robert J et al. (2014) Probing the electrostatics of active site microenvironments along the catalytic cycle for Escherichia coli dihydrofolate reductase. J Am Chem Soc 136:10349-60
Talukder, Poulami; Chen, Shengxi; Liu, C Tony et al. (2014) Tryptophan-based fluorophores for studying protein conformational changes. Bioorg Med Chem 22:5924-34
Talukder, Poulami; Chen, Shengxi; Arce, Pablo M et al. (2014) Efficient asymmetric synthesis of tryptophan analogues having useful photophysical properties. Org Lett 16:556-9
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Chen, Shengxi; Fahmi, Nour Eddine; Bhattacharya, Chandrabali et al. (2013) Fluorescent biphenyl derivatives of phenylalanine suitable for protein modification. Biochemistry 52:8580-9
Chen, Shengxi; Fahmi, Nour Eddine; Wang, Lin et al. (2013) Detection of dihydrofolate reductase conformational change by FRET using two fluorescent amino acids. J Am Chem Soc 135:12924-7
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