@conference {441, title = {Anisotropic Terahertz Microscopy of Lysozyme in Different CrystalLattice Systems}, booktitle = {Biophysical Journal}, year = {2021}, month = {02/2021}, abstract = {

Long-range vibrational modes of proteins at terahertz (THz) frequencies havebeen associated with protein function and allosteric control. The characteriza-tion of these motions has been challenging due to energy overlap with waterabsorption and a large vibrational density of states. Recently it has been demon-strated both experimentally and theoretically that vibrational bands can be iso-lated using stationary sample anisotropic terahertz microscopy (SSTAM) fororiented samples, typically realized using protein crystals [1, 2]. In those earlymeasurements, inhibitor binding contrast was demonstrated for high symmetrytetragonal crystals. While high symmetry crystals are ideal for structural deter-minations, they can limit the types of vibrations observable in the ATM mea-surements. Here we show a survey of ATM measurements of triclinic,monoclinic and tetragonal crystals, demonstrating the unique signaturesobservable for the different symmetry groups, leading to a more completedetermination of the vibrational hot spots that may contribute to enzymatic ef-ficiency. The SSATM spectra indicate the presence of conserved vibrationalmodes near 40 cm-1 and 55 cm-1 for CEWL in triclinic, monoclinic and tetrag-onal lattice systems respectively. For CEWL in the monoclinic lattice system, aprominent band at 20cm1was consistently observed in the SSATM spectrabut not in the triclinic or tetragonal systems. The conserved bands may repre-sent vibrational modes that are unperturbed by crystal contact forces while thedifferences may be related to unique molecular orientation in different crystalsystems.


1.Niessen, K., Y. Deng, and A.G. Markelz,Near-field THz micropo-larimetry.Opt Express, 2019.27(20): p. 28036-28047.

2.Romo, T.D., A.Grossfield, and A.G. MarkelzPersistent Protein Motions in a RuggedEnergy Landscape Revealed by Normal Mode Ensemble Analysis. AcceptedJournal of Chemical Information and Modeling, 2020.

}, doi = {10.1016/j.bpj.2020.11.972}, url = {https://www.cell.com/biophysj/fulltext/S0006-3495(20)31879-8}, author = {McKinney, J. A. and George, D. K. and Deng, Y. and Markelz, A. G.} } @article {329, title = {Near-Field Stationary Sample Terahertz Spectroscopic Polarimetry for Biomolecular Structural Dynamics Determination}, journal = {ACS Photonics}, volume = {8}, year = {2021}, month = {02/2021}, pages = {658-668}, chapter = {658}, abstract = {

THz polarimetry on environmentally sensitive and microscopic samples can provide unique insight into underlying mechanisms of complex phenomena. For example, near-field THz anisotropic absorption successfully isolated protein structural vibrations which are connected to biological function. However, to determine how these vibrations impact function requires high throughput measurements of these complex systems, which is challenged by the need for near field detection, sample environmental control and full polarization variation. Stationary sample anisotropic terahertz spectroscopy (SSATS) and near-field stationary sample anisotropic terahertz microscopy (SSATM) have been proposed using synchronous control of THz and electro optic probe polarizations along an iso-response curve. Here we realize these techniques through robust control and calibration of the THz and NIR polarization states. Both methods rapidly measure the linear dichroism in the far field and near field. Validation measurements using standard birefringent sucrose single crystals found the crystal orientation can be determined by scanning the reference polarization and the synchronous pump{\textendash}probe polarization settings can be optimized to eliminate artifacts. SSATM is then used to determine spectral reproducibility and dehydration effects for a series of chicken egg white lysozyme samples. Reproducible anisotropic absorbance bands are found at about 30, 44, 55, and 62 cm{\textendash}1. These bands initially sharpen with slow dehydration, similar to the increase in resolution achieved in X-ray crystallographic protein structure determination. The SSATM technique confirms the reliability of anisotropic absorption characterization of protein intramolecular vibrations and opens an avenue for rapid determination of how these long-range dynamics affect biological function.

}, doi = {10.1021/acsphotonics.0c01876}, url = {https://pubs.acs.org/doi/abs/10.1021/acsphotonics.0c01876}, author = {Deng, Y. and McKinney, J. A. and George, D. K. and Niessen, K. A. and Sharma, A. and Markelz, A.G.} } @article {253, title = {Evidence of Intramolecular Structural Stabilization in Light Activated State of Orange Carotenoid Protein}, journal = {Biophysical Journal}, volume = {118}, number = {3}, year = {2020}, note = {ISI Document Delivery No.: KK8YX
Times Cited: 0
Cited Reference Count: 0
McKinney, Jeffrey A. Sharma, Akansha Crossen, Kimberly Deng, Yanting George, Deepu K. Lechno-Yossef, Sigal Kerfeld, Cheryl Markelz, Andrea G.
64th Annual Meeting of the Biophysical-Society
Feb 15-19, 2020
San Diego, CA
Biophys Soc
NSFNational Science Foundation (NSF) [DBI 1556359, MCB 1616529]; DOEUnited States Department of Energy (DOE) [DE-SC0016317]; NIH STTRUnited States Department of Health \& Human ServicesNational Institutes of Health (NIH) - USA [R41 GM125486]
This work is supported by NSF grants DBI 1556359 and MCB 1616529, DOE grant DE-SC0016317 and NIH STTR R41 GM125486.

1
2
Cell press
Cambridge
1542-0086}, month = {Feb}, pages = {208A-208A}, type = {Meeting Abstract}, abstract = {

Orange carotenoid protein (OCP) controls efficiency of the light harvesting antenna, the phycobilisome (PBS), in diverse cyanobacteria and prevents oxidative damage. It is the only known photoactive protein that uses a carotenoid, canthaxanthin, as its chromophore. The structure of OCP consists of two globular domains, connected by an unstructured loop, that forms a hydrophobic pocket for the carotenoid. In low light, canthaxanthin bound OCP is inactive and appears orange. Illumination by strong light results in an active state that interacts with the PBS to induce fluorescence quenching, a red appearance and conformational changes that include a 12{\r A} shift by canthaxanthin into the N-terminal domain. Terahertz (THz) dynamical transition measurements and anisotropic terahertz microscopy are used to measure the intramolecular structural dynamics in the inactive and active states, which can be induced by photoexcitation or chaotropic salts. The measurements indicate that the active state has a decrease in structural flexibility, which may be related to enhanced interactions with the PBS.

}, keywords = {Biophysics}, isbn = {0006-3495}, doi = {10.1016/j.bpj.2019.11.1245}, author = {McKinney, J. A. and Sharma, A. and Crossen, K. and Deng, Y. and George, D. K. and Lechno-Yossef, S. and Kerfeld, C. and Markelz, A. G.} } @article {252, title = {Long Range Correlated Motions of TIM and their Possible Influence on Enzyme Function}, journal = {Biophysical Journal}, volume = {118}, number = {3}, year = {2020}, note = {ISI Document Delivery No.: KK8YX
Times Cited: 0
Cited Reference Count: 4
Cited References:
Acbas G, 2014, NAT COMMUN, V5, DOI 10.1038/ncomms4076
Niessen K.A. M.Y., 2017, BIOPHYS J, DOI [10.1016/j.bpj.2016.12.049.3., DOI 10.1016/J.BPJ.2016.12.049.3]
Niessen K, 2019, OPT EXPRESS, V27, P28036, DOI 10.1364/OE.27.028036
Niessen KA, 2019, NAT COMMUN, V10, DOI 10.1038/s41467-019-08926-3
McKinney, Jeffrey A. Deng, Yanting George, Deepu K. Richard, John Markelz, Andrea G.
64th Annual Meeting of the Biophysical-Society
Feb 15-19, 2020
San Diego, CA
Biophys Soc
NSFNational Science Foundation (NSF) [DBI 1556359, MCB 1616529]; DOEUnited States Department of Energy (DOE) [DE-SC0016317]; NIH STTRUnited States Department of Health \& Human ServicesNational Institutes of Health (NIH) - USA [R41 GM125486.1]
This work is supported by NSF grants DBI 1556359 and MCB 1616529, DOE grant DE-SC0016317 and NIH STTR R41 GM125486.1.

1
Cell press
Cambridge
1542-0086}, month = {Feb}, pages = {207A-207A}, type = {Meeting Abstract}, abstract = {

The alpha-beta barrel structure of triosephosphate isomerase (TIM) is possibly the most common among enzymes. In the case of TIM, structural dynamics are known to be essential to function. In particular the stabilization of the binding pocket by a phosphodianion {\textquotedblleft}handle{\textquotedblright} of the substrate and the closing of catalytic site loops 6 and 7 over the substrate. Loop 6 moves by as much as 7 Angstroms with binding. Recently a mutant survey for human TIM (hsTIM) found kcat can change significantly for a single mutation distant from the catalytic site. Crystallographic measurements find no structural change with the mutation, suggesting a dynamical mechanism for the allosteric effect. Here we use Stationary Sample Anisotropic Terahertz Microscopy (SSATM) to measure the long-range intramolecular vibrations and determine if specific vibrations couple the allosteric and catalytic sites. SSATM isolated protein long-range structural vibrations based on the dominant displacement direction [1-4]. We examine if specific vibrational bands are associate with loop 6 and loop 7 flexibility.

}, keywords = {Biophysics}, isbn = {0006-3495}, doi = {10.1016/j.bpj.2019.11.1240}, author = {McKinney, J. A. and Deng, Y. T. and George, D. K. and Richard, J. and Markelz, A. G.} } @article {251, title = {The Effect of Crystal Contact Forces on the Protein Global Motions}, journal = {Biophysical Journal}, volume = {116}, number = {3}, year = {2019}, note = {ISI Document Delivery No.: HO2XG
Times Cited: 0
Cited Reference Count: 1
Cited References:
Acbas G, 2014, NAT COMMUN, V5, DOI 10.1038/ncomms4076
McKinney, Jeffrey A. Deng, Yanting George, Deepu Markelz, Andrea
63rd Annual Meeting of the Biophysical-Society
Mar 02-06, 2019
Baltimore, MD
Biophys Soc

8
Cell press
Cambridge
1542-0086
1}, month = {Feb}, pages = {489A-489A}, type = {Meeting Abstract}, keywords = {Biophysics}, isbn = {0006-3495}, doi = {10.1016/j.bpj.2018.11.2638}, author = {McKinney, J. A. and Deng, Y. T. and George, D. and Markelz, A.} }