Researchers in the Thomas laboratory use spectroscopic probes to study the role of protein structure and dynamics in physiological processes, particularly in muscle fibers and membranes. Site-directed mutagenesis and cell culture techniques are used to attach spectroscopic molecular probes to study selected components within intact and functional molecular assemblies. This laboratory is unique in its combination of state-of-the-art instrumentation and expertise in both magnetic resonance (EPR and NMR) and optical (laser) spectroscopy and imaging (fluorescence, phosphorescence, luminescence).
In the muscle fiber studies, mechanical, biochemical, and spectroscopic experiments are used to correlate the functional state of a muscle fiber with the orientation and motion of specifically labeled proteins (myosin or actin), thus providing direct tests for models of the mechanism of force generation. The main membrane system studied is the calcium pump of sarcoplasmic reticulum. Spectroscopic probes are used to determine which molecular structures and motions are essential for active calcium transport and its regulation, particularly in the heart, where phospholamban plays a crucial role in regulation. Some projects are focused on the fundamental biophysics of normal muscle; other projects are applied to specific medical problems, such as aging or inherited muscle disease or molecular therapeutic design. Workers in the laboratory include undergraduate students, postdoctoral fellows, and graduate students associated with Biochemistry, Biophysics, Biomedical Engineering, and Neuroscience programs.
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
- Chu S, Muretta JM, Thomas DD. Direct detection of the myosin super-relaxed state and interacting-heads motif in solution. J Biol Chem. 2021 Sep 2;297(4):101157.
- Roopnarine O, Thomas DD. Mechanistic analysis of actin-binding compounds that affect the kinetics of cardiac myosin-actin interaction. J Biol Chem. 2021 Jan-Jun;296:100471.
- Li A, Yuen SL, Stroik DR, Kleinboehl E, Cornea RL, Thomas DD. The transmembrane peptide DWORF activates SERCA2a via dual mechanisms. J Biol Chem. 2021 Jan-Jun;296:100412.
- Nelson SED, Weber DK, Rebbeck RT, Cornea RL, Veglia G, Thomas DD. Met125 is essential for maintaining the structural integrity of calmodulin's C-terminal domain. Sci Rep. 2020 Dec 7;10(1):21320.
- Nelson SED, Ha KN, Gopinath T, Exline MH, Mascioni A, Thomas DD, Veglia G. Effects of the Arg9Cys and Arg25Cys mutations on phospholamban's conformational equilibrium in membrane bilayers. Biochim Biophys Acta. 2018 Mar 2;1860(6):1335-1341.
- Ruff EF, Muretta JM, Thompson AR, Lake EW, Cyphers S, Albanese SK, Hanson SM, Behr JM, Thomas DD, Chodera JD, Levinson NM. A dynamic mechanism for allosteric activation of Aurora kinase A by activation loop phosphorylation. Elife. 2018 Feb 21;7.
- Muretta JM, Reddy BJN, Scarabelli G, Thompson AF, Jariwala S, Major J, Venere M, Rich JN, Willard B, Thomas DD, Stumpff J, Grant BJ, Gross SP, Rosenfeld SS. A posttranslational modification of the mitotic kinesin Eg5 that enhances its mechanochemical coupling and alters its mitotic function. Proc Natl Acad Sci U S A. 2018 Feb 20;115(8):E1779-E1788.
- Fealey ME, Binder BP, Uversky VN, Hinderliter A, Thomas DD. Structural Impact of Phosphorylation and Dielectric Constant Variation on Synaptotagmin's IDR. Biophys J. 2018 Feb 6;114(3):550-561.
- O'Rourke AR, Lindsay A, Tarpey MD, Yuen S, McCourt P, Nelson DM, Perrin BJ, Thomas DD, Spangenburg EE, Lowe DA, Ervasti JM. Impaired muscle relaxation and mitochondrial fission associated with genetic ablation of cytoplasmic actin isoforms.
- O'Rourke AR, Lindsay A, Tarpey MD, Yuen S, McCourt P, Nelson DM, Perrin BJ, Thomas DD, Spangenburg EE, Lowe DA, Ervasti JM. FEBS J. 2017 Dec 18. doi: 10.1111/febs.14367
- Avery AW, Thomas DD, Hays TS. β-III-spectrin spinocerebellar ataxia type 5 mutation reveals a dominant cytoskeletal mechanism that underlies dendritic arborization.Proc Natl Acad Sci U S A. 2017;114(44):E9376-E9385.
- Colson BA, Thompson AR, Espinoza-Fonseca LM, Thomas DD. Site-directed spectroscopy of cardiac myosin-binding protein C reveals effects of phosphorylation on protein structural dynamics. Proc Natl Acad Sci U S A. 2016;113(12):3233-8.
- McCaffrey JE, James ZM, Svensson B, Binder BP, Thomas DD. A bifunctional spin label reports the structural topology of phospholamban in magnetically-aligned bicelles. J Magn Reson. 2016;262:50-6.
- Muretta JM, Jun Y, Gross SP, Major J, Thomas DD, Rosenfeld SS. The structural kinetics of switch-1 and the neck linker explain the functions of kinesin-1 and Eg5. Proc Natl Acad Sci U S A. 2015;112(48):E6606-13.
- Trivedi DV, Muretta JM, Swenson AM, Davis JP, Thomas DD, Yengo CM. Direct measurements of the coordination of lever arm swing and the catalytic cycle in myosin V. Proc Natl Acad Sci U S A. 2015;112(47):14593-8.
- Muretta JM, Rohde JA, Johnsrud DO, Cornea S, Thomas DD. Direct real-time detection of the structural and biochemical events in the myosin power stroke. Proc Natl Acad Sci U S A. 2015;112(46):14272-7.
- Oda T, Yang Y, Uchinoumi H, Thomas DD, Chen-Izu Y, Kato T, Yamamoto T, Yano M, Cornea RL, Bers DM. Oxidation of ryanodine receptor (RyR) and calmodulin enhance Ca release and pathologically alter, RyR structure and calmodulin affinity. J Mol Cell Cardiol. 2015;85:240-8.
- Binder BP, Cornea S, Thompson AR, Moen RJ, Thomas DD. High-resolution helix orientation in actin-bound myosin determined with a bifunctional spin label. Proc Natl Acad Sci U S A. 2015;112(26):7972-7.
- Espinoza-Fonseca LM, Alamo L, Pinto A, Thomas DD, Padrón R. Sequential myosin phosphorylation activates tarantula thick filament via a disorder-order transition. Mol Biosyst. 2015;11(8):2167-79.
- Espinoza-Fonseca LM, Autry JM, Thomas DD. Sarcolipin and phospholamban inhibit the calcium pump by populating a similar metal ion-free intermediate state. Biochem Biophys Res Commun. 2015;463(1-2):37-41.
- Iram SH, Gruber SJ, Raguimova ON, Thomas DD, Robia SL. ATP-binding cassette transporter structure changes detected by intramolecular fluorescence energy transfer for high-throughput screening. Mol Pharmacol. 2015;88(1):84-94.
- Espinoza-Fonseca LM, Autry JM, Ramírez-Salinas GL, Thomas DD. Atomic-level mechanisms for phospholamban regulation of the calcium pump. Biophys J. 2015;108(7):1697-708.
- Guhathakurta P, Prochniewicz E, Thomas DD. Amplitude of the actomyosin power stroke depends strongly on the isoform of the myosin essential light chain. Proc Natl Acad Sci U S A. 2015;112(15):4660-5
- McCaffrey JE, James ZM, Thomas DD. Optimization of bicelle lipid composition and temperature for EPR spectroscopy of aligned membranes. J Magn Reson. 2015;250:71-5.
- Svensson B, Oda T, Nitu FR, Yang Y, Cornea I, Chen-Izu Y, Fessenden JD, Bers DM, Thomas DD, Cornea RL. FRET-based trilateration of probes bound within functional ryanodine receptors. Biophys J. 2014;107(9):2037-48.
- Lewis AK, James ZM, McCaffrey JE, Braun AR, Karim CB, Thomas DD, Sachs JN. Open and closed conformations of the isolated transmembrane domain of death receptor 5 support a new model of activation. Biophys J. 2014;106(6):L21-4.
Current Graduate Students:
Simon Gruber (Biochemistry)
Suzanne Haydon (Biochemistry)
Zach James (Biochemistry)
David Kast (Biochemistry)
Yun Lin (MD/PhD)
Elizabeth Lockamy (Biochemistry)
Jesse McCaffrey (Physics)
Ryan Mello (Biophysics)
Rebecca Moen (Biochemistry)
Former Graduate Students:
Jack Grinband (Ph.D. 2002, Neuroscience, Univesity of Minnesota).
John Stamm (Biochemistry).
Josh Baker (Biochemistry).
Min Zhao (Chemistry).
Ming Li (Biochemistry).
John Voss (Biochemistry).
Brad Karon (Neuroscience).
Scott Lewis (Neuroscience).
Leslie LaConte (Biochemistry).
Wendy Smith (Biochemistry).
Tara Kirby (Biochemistry).
Diane Eschliman (Biophysical Sciences).
Ben Mueller (MD/PhD).
Jack Surek (Biochemistry).
Jennifer Klein (Biochemistry).
David Kast (Physics).
Brian Wiczer (Biochemistry).