Positions

Overview

  • The Varga lab focuses on the biophysical characterization of protein structure and function. We use NMR and other spectroscopic techniques to investigate protein structure, protein-protein, and protein-ligand interactions. Another major research interest is the design and characterization of chiral nanoparticles. Ongoing projects include:

    ANTIFREEZE PROTEINS
    Antifreeze proteins are found in a wide range of cold adapted organisms, and they contribute to their freeze resistance. Antifreeze proteins adsorb to the ice surface and inhibit the growth of ice crystals. The goal of this project is to investigate the mechanism by which antifreeze proteins protect against the damage typically inflicted by cold, including the underlying molecular mechanism of ice-binding. This project is supported by NASA-EPSCoR and NIH.

    CHIRAL NANOPARTICLES
    Quantum dots (QDs) are nanometer size semiconductor crystals with excellent and tunable electronic and optical properties. Colloidal quantum dots consist of an inorganic semiconductor core (e.g. CdSe) and an organic capping ligand shell (e.g. cysteine). We aim to determine how chiral organic ligands induce chiroptical activity in achiral semiconductor QDs and how QDs can be used to enhance the chiroptical signal of biomolecules. Chiral QDs are promising candidates for bioimaging, biosensing, environmental nanoassays, catalysis, and chiral memory. his project was supported by NSF.

    REGULATORS OF G-PROTEIN SIGNALING PROTEINS
    The discoveries of a class of intracellular regulatory proteins known as regulators of G-protein signaling (RGS) proteins that mediate GPCR signaling via protein-protein interactions between the RGS domains and the gamma-subunit of G-proteins and their covalent inhibitors have opened a new venue for allosteric targeting in GPCRs. We are studying inhibitor-induced structural perturbations using NMR and MD analyses of the RGS8 protein and its mutant forms to understand the role of cysteine residues in affecting potency and specificity of inhibitors. This project is supported by NIH.

    RATES OF PROTEIN EVOLUTION
    We aim to identify the factors that have an important impact on the rates of protein evolution and elucidate the reasons why these factors affect rates of evolution. During evolution, different proteins accumulate amino acid changes at enormously different rates as a result of the different selective pressures to which they are subjected. This project is supported by NSF.

    BACTERIAL MECHANISMS IN ESTABLISHING AND MAINTAINING CELL POLARITY
    The polar organizing protein Z (PopZ) is necessary for the formation of three-dimensional microdomains at the cell poles in Caulobacter crescentus, where it functions as a hub protein that recruits multiple regulatory proteins from the cytoplasm. Although a large portion of the protein is predicted to be natively unstructured, in reconstituted systems PopZ can self-assemble into a macromolecular scaffold that directly binds to at least ten different proteins. We have utilized NMR spectroscopy to study its interaction with its binding partners. This project was supported by NIH.
  • Selected Publications

    Academic Article

    Year Title
    2024 Phospho-signaling couples polar asymmetry and proteolysis within a membraneless microdomain in Caulobacter crescentus.Nature Communications.  15:9282. 2024
    2023 Threonine functionalized colloidal cadmium sulfide (CdS) quantum dots: The role of solvent and counterion in ligand induced chiroptical properties.Journal of Colloid and Interface Science.  642:771-778. 2023
    2022 Molecular interactions and inhibition of the SARS-CoV-2 main protease by a thiadiazolidinone derivative.Proteins: Structure, Function, and Bioinformatics.  90:1896-1907. 2022
    2022 Intracellular and Extracellular Antifreeze Protein Significantly Improves Mammalian Cell Cryopreservation.Biomolecules.  12:669. 2022
    2022 An insect antifreeze protein from Anatolica polita enhances the cryoprotection of Xenopus laevis eggs and embryos.The Journal of Experimental Biology.  225:jeb243662. 2022
    2022 Apple juice and red wine induced mirror-image circular dichroism in quantum dots.Chirality: the pharmacological, biological, and chemical consequences of molecular asymmetry .  34:70-76. 2022
    2021 The effect of molecular isomerism on the induced circular dichroism of cadmium sulfide quantum dotsJournal of Materials Chemistry C.  9:17483-17495. 2021
    2021 Large-Scale Recombinant Production of the SARS-CoV-2 Proteome for High-Throughput and Structural Biology Applications.Frontiers in Molecular Biosciences.  8:653148. 2021
    2020 Intrinsically Disordered Bacterial Polar Organizing Protein Z, PopZ, Interacts with Protein Binding Partners Through an N-terminal Molecular Recognition Feature.Journal of Molecular Biology.  432:6092-6107. 2020
    2020 Structural Analysis of the Regulatory GAF Domains of cGMP Phosphodiesterase Elucidates the Allosteric Communication Pathway.Journal of Molecular Biology.  432:5765-5783. 2020
    2020 Functional Nanoassemblies with Mirror-Image Chiroptical Properties Templated by a Single Homochiral DNA StrandChemistry of Materials.  32:2272-2281. 2020
    2019 Changes in Cryopreserved Cell Nuclei Serve as Indicators of Processes during Freezing and Thawing.Langmuir: the ACS journal of surfaces and colloids.  35:7496-7508. 2019
    2018 Chromatin architecture changes and DNA replication fork collapse are critical features in cryopreserved cells that are differentially controlled by cryoprotectants.Scientific Reports.  8:14694. 2018
    2017 CdSe Quantum Dots Functionalized with Chiral, Thiol-Free Carboxylic Acids: Unraveling Structural Requirements for Ligand-Induced Chirality.ACS Nano.  11:9846-9853. 2017
    2017 Organic coating on biochar explains its nutrient retention and stimulation of soil fertility.Nature Communications.  8:1089. 2017
    2017 Chiral multichromophoric supramolecular nanostructures assembled by single stranded DNA and RNA templatesCoordination Chemistry Reviews.  349:66-83. 2017
    2017 Theoretical and experimental study of the antifreeze protein AFP752, trehalose and dimethyl sulfoxide cryoprotection mechanism: correlation with cryopreserved cell viability.RSC Advances: an international journal to further the chemical sciences.  7:352-360. 2017
    2016 The effects of high concentrations of ionic liquid on GB1 protein structure and dynamics probed by high-resolution magic-angle-spinning NMR spectroscopy.Biochemistry and Biophysics Reports.  8:75-80. 2016
    2016 Caulobacter PopZ forms an intrinsically disordered hub in organizing bacterial cell poles.Proceedings of the National Academy of Sciences of USA.  113:12490-12495. 2016
    2016 Chirality Inversion of CdSe and CdS Quantum Dots without Changing the Stereochemistry of the Capping Ligand.ACS Nano.  10:3809-3815. 2016
    2015 ¹³C- and ¹H-detection under fast MAS for the study of poorly available proteins: application to sub-milligram quantities of a 7 trans-membrane protein.Journal of Biomolecular NMR.  62:17-23. 2015
    2014 Characterization of the mechanism of gasification of a powder river basin coal with a composite catalyst for producing desired syngases and liquidsApplied Catalysis A: General.  475:116-126. 2014
    2013 Ligand induced circular dichroism and circularly polarized luminescence in CdSe quantum dots.ACS Nano.  7:11094-11102. 2013
    2013 Achiral CdSe quantum dots exhibit optical activity in the visible region upon post-synthetic ligand exchange with D- or L-cysteine.Chemical Communications.  49:1844-1846. 2013
    2012 Targeting the lateral interactions of transmembrane domain 5 of Epstein-Barr virus latent membrane protein 1.BBA: Biomembranes.  1818:2282-2289. 2012
    2011 Ermittlung der Konformation von Bacteriorhodopsin‐Peptidschleifen in Purpurmembranen durch Festkörper‐MAS‐NMR‐SpektroskopieAngewandte Chemie International Edition.  123:8583-8586. 2011
    2011 The conformation of bacteriorhodopsin loops in purple membranes resolved by solid-state MAS NMR spectroscopy.Angewandte Chemie International Edition.  50:8432-8435. 2011
    2011 Structure of the BamC two-domain protein obtained by Rosetta with a limited NMR data set.Journal of Molecular Biology.  411:83-95. 2011
    2008 Advances towards resonance assignments for uniformly--13C, 15N enriched bacteriorhodopsin at 18.8 T in purple membranes.Journal of Biomolecular NMR.  41:1-4. 2008
    2007 NMR crystallography: the effect of deuteration on high resolution 13C solid state NMR spectra of a 7-TM protein.BBA: Biomembranes.  1768:3029-3035. 2007
    2007 Solid-state NMR study and assignments of the KcsA potassium ion channel of S. lividans.BBA: Proteins and Proteomics.  1774:1604-1613. 2007

    Chapter

    Year Title
    2019 Structure and Electronic Circular Dichroism of Chiral Porphyrins and Chiral Porphyrin Dimers.  205-284. 2019
    2016 Templated Porphyrin Assemblies Using Bio-Inspired Scaffolds — Covalent and Non-Covalent Approaches.  31-128. 2016
    2007 Introduction to Solid‐State NMR and its Application to Membrane Protein–Ligand Binding Studies.  55-87. 2007

    Conference Paper

    Year Title
    2015 Origin and tuning of chirality in quantum dotsACS National Meeting Book of Abstracts. 2015
    2015 Structural and functional characterization of the antifreeze protein ApAFP752ACS National Meeting Book of Abstracts. 2015
    2015 Structural and functional studies of TSPOACS National Meeting Book of Abstracts. 2015

    Co-principal Investigator On

    Teaching Activities

  • Doctoral Research Taught course
  • Doctoral Research Taught course
  • Honors Senior Thesis Taught course
  • Principles of Biochemistry Taught course
  • Principles of Biochemistry I Taught course
  • Principles of Biochemistry II Taught course
  • Principles of Biochemistry II Taught course
  • Doctoral Research Taught course 2024
  • Honors Senior Thesis Taught course 2024
  • Doctoral Thesis Taught course 2023
  • Doctoral Thesis Taught course 2022
  • Principles of Biochemistry Taught course 2022
  • Principles of Biochemistry I Taught course 2022
  • Doctoral Thesis Taught course 2022
  • General Biochemistry Taught course 2022
  • General Biochemistry Taught course 2022
  • Honors Senior Thesis Taught course 2022
  • Student Research Experience Taught course 2022
  • Doctoral Thesis Taught course 2021
  • Honors Senior Thesis Taught course 2021
  • Principles of Biochemistry I Taught course 2021
  • Doctoral Thesis Taught course 2021
  • Honors Senior Thesis Taught course 2021
  • Physical Biochemistry Taught course 2021
  • Doctoral Thesis Taught course 2020
  • Honors Senior Thesis Taught course 2020
  • Principles of Biochemistry I Taught course 2020
  • Doctoral Thesis Taught course 2020
  • Physical Biochemistry Taught course 2020
  • Doctoral Thesis Taught course 2019
  • Principles of Biochemistry I Taught course 2019
  • Doctoral Thesis Taught course 2019
  • General Biochemistry Taught course 2019
  • Physical Biochemistry Taught course 2019
  • Doctoral Thesis Taught course 2018
  • Intro to Research in Life Sci Taught course 2018
  • Principles of Biochemistry I Taught course 2018
  • Doctoral Research Taught course 2018
  • Doctoral Research Taught course 2018
  • Physical Biochemistry Taught course 2018
  • Doctoral Research Taught course 2017
  • General Biochemistry Taught course 2017
  • General Biochemistry Taught course 2017
  • Intro to Research in Life Sci Taught course 2017
  • Doctoral Research Taught course 2017
  • Physical Biochemistry Taught course 2017
  • Doctoral Research Taught course 2016
  • Intro to Research in Life Sci Taught course 2016
  • Education And Training

  • B.S. Chemistry, St. John’s University
  • M.S. Biology, St. John’s University
  • Ph.D. Chemistry, Columbia University
  • Full Name

  • Krisztina Varga