03325nas a2200145 4500008004100000245008500041210006900126260001200195520283400207100002103041700001903062700001303081700002003094856006503114 2021 eng d00aAnisotropic Terahertz Microscopy of Lysozyme in Different CrystalLattice Systems0 aAnisotropic Terahertz Microscopy of Lysozyme in Different Crysta c02/20213 a

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.

1 aMcKinney, J., A.1 aGeorge, D., K.1 aDeng, Y.1 aMarkelz, A., G. uhttps://www.cell.com/biophysj/fulltext/S0006-3495(20)31879-801175nas a2200145 4500008004100000022001500041245004900056210004800105260002500153520072700178100002300905700002000928700002700948856005400975 2021 eng d a11,125,68500aApparatus and method for analyzing a sample 0 aApparatus and method for analyzing a sample aUnited StatesbUSPTO3 a
An apparatus and method for Crystal Anisotropy Terahertz Microscopy (“CATM”) is provided. The apparatus includes an emitter configured to emit a THz pulse and a detector configured to detect the THz pulse after the pulse is transmitted through a sample disposed on a sample surface of the detector. A pulsed radiation generator generates a probe beam to interrogate the detector. The detector may include an electro-optical (“EO”) crystal configured to change in birefringence according to the THz pulse. The sample surface of the detector may have a dielectric coating which is transmissive to THz and reflective to the probe beam. The sample is disposed on the dielectric coating.
1 aMarkelz, Andrea, G1 aAcbas, Gheorghe1 aNiessen, Katherine, A. uhttps://patents.google.com/patent/US11125685B2/en01834nas a2200385 4500008004100000020001400041245007100055210006900126260002400195300001000219520062400229653001500853653003100868653002700899653003400926653003400960653004300994653001501037653002301052653003001075653001501105653001301120653004501133653002701178653001701205653002201222653002701244653002701271653004101298653001501339100001301354700001601367700001601383856004901399 2019 eng d a2162-203500aAngular Distortion Removal of THz Anisotropic Dichroism Microscope0 aAngular Distortion Removal of THz Anisotropic Dichroism Microsco aParis, Francec2019 a1 - 23 a

We have developed a stationary sample THz anisotropic dichroism microscope as a powerful tool for material characterization. The key innovation is the use of an iso-response curve defined by the terahertz and detection light polarizations. Here we show that following a continuous iso-response curve introduces angular distortion in the spectrum, and this distortion can be eliminated by using a discontinuous iso-response angle pairs avoiding large gradient regions. Employing this additional constraint on the relative polarizations provides a convenient technique for rapid anisotropic terahertz spectroscopy.

10aabsorption10aangular distortion removal10aBiomedical measurement10acontinuous iso-response curve10adetection light polarizations10adiscontinuous iso-response angle pairs10aDistortion10alight polarisation10amaterial characterization10aMicroscopy10aproteins10arapid anisotropic terahertz spectroscopy10arelative polarizations10aspectroscopy10astationary sample10aterahertz spectroscopy10aterahertz wave spectra10aTHz anisotropic dichroism microscope10avibrations1 aDeng, Y.1 aNiessen, K.1 aMarkelz, A. uhttps://ieeexplore.ieee.org/document/887379301100nas a2200169 4500008004500000020002200045245011300067210006900180260001900249520052500268100001700793700001700810700001500827700001900842700002000861856004900881 2019 Engldsh  a978-1-5386-8285-200aAnisotropic Terahertz Microscopy of Protein Collective Vibrations: Crystal Symmetry and Hydration Dependence0 aAnisotropic Terahertz Microscopy of Protein Collective Vibration aNew YorkbIeee3 a

A stationary sample anisotropic terahertz microscopy technique is used to characterize the intramolecular vibrations for lysozyme. Tetragonal and triclinic crystals are compared. We find excellent reproducibility within a single crystal symmetry group. Several resonant bands are present for both symmetry groups, indicating they originate with the intramolecular vibrations and not crystal lattice phonons. Bands become more pronounced and higher frequency resonant bands begin to emerge with slight dehydration.

1 aMcKinney, J.1 aDeng, Y., T.1 aSharma, A.1 aGeorge, D., K.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/23501585nas a2200181 4500008004500000020002200045245010500067210006900172260001900241520099700260100001501257700001601272700001501288700001701303700001401320700002001334856004901354 2016 Engldsh  a978-1-4673-8485-800aAnisotropic Absorption Measurements Reveal Protein Dynamical Transition in Intramolecular Vibrations0 aAnisotropic Absorption Measurements Reveal Protein Dynamical Tra aNew YorkbIeee3 a

Modeling has predicted that intramolecular structural vibrations enables proteins to access functionally important structural change. We show that the vibrational density of states and the isotropic absorption in the terahertz range are only weakly dependent on the protein functional state for several bench marking proteins. At the same time the direction of motions changes dramatically with functional state and with a resulting impact on the anisotropic absorption. Our anisotropic THz microscopy (ATM) measurements confirm this sensitivity. Here we apply the technique to the question of whether the protein dynamical transition (DT) is important to protein function. We find a strong anisotropic resonance at 70 cm(-1) rapidly increases in strength at temperatures above the DT. As these intramolecular vibrations enable protein structure to change conformation, the results suggest function will cease below DT for those proteins that require large scale conformational change.

1 aXu, M., Y.1 aNiessen, K.1 aMichki, N.1 aDeng, Y., T.1 aSnell, E.1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/246