01175nas 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/en00552nas a2200181 4500008004100000020001400041245006300055210006300118260001000181300001400191490000800205100002700213700001700240700001800257700002200275700002400297856004900321 2017 eng d a0006-349500aImportance of Protein Vibration Directionality on Function0 aImportance of Protein Vibration Directionality on Function cFeb 3 a353A-353A0 v1121 aNiessen, Katherine, A.1 aXu, Mengyang1 aDeng, Yanting1 aSnell, Edward, H.1 aMarkelz, Andrea, G. uhttps://markelz.physics.buffalo.edu/node/25402250nas a2200157 4500008004100000245009400041210006900135260001700204520170800221100001801929700001701947700002701964700002001991700002402011856005702035 2016 eng d00aDirect Measurements of the Long-Range Collective Vibrations of Photoactive Yellow Protein0 aDirect Measurements of the LongRange Collective Vibrations of Ph aBaltimore MD3 a

Long-range collective vibrations are thought to be crucial to protein functions. In the case of photoactive protein family, modeling suggests the intramolecular vibrations provide an efficient means of energy relaxation[1], feedback for enhancement of chromophore vibrations that promote structural transitions[2] and can assist in charge energy transfer[3]. As a paradigm of this family, photoactive yellow protein (PYP) is a cytoplasmic photocycling protein related to negative phototactic response to blue light in purple photosynthetic bacteria. PYP has a p-coumaric acid chromophore binding to the cysteine residue via a thioester bond, whose vibrations were found to overlap calculated vibrations of the protein scaffold. Using our unique technique of anisotropic terahertz microscopy(ATM)[4], we measure the intramolecular vibrations for PYP for the first time, including cycling between ground and blue shift (pB) states. Room temperature ATM measurements are performed in the dark and with continuous wave illumination at 488nm, resulting in a steady pB state with approximately 5% population conversion. In pB state, we find an overall decrease in the strength of resonant band in frequency range of 30-60 cm-1. Our calculated spectra using quasi-harmonic analysis indicate that our measurements are dominated by the protein vibrations, rather than the pCA chromophore, allowing us to characterize how the scaffold dynamics changes with functional states and mutations.

1. Levantino, M., et al. Nat Commun, 2015. 6.

2. Mataga, N., et al. Chem. Phys. Lett., 2002. 352(3-4): p. 220-225.

3. Fokas, A.S., et al. Photosynth. Res., 2014. 122

1 aDeng, Yanting1 aXu, Mengyang1 aNiessen, Katherine, A.1 aSchmidt, Marius1 aMarkelz, Andrea, G. uhttps://onlinelibrary.wiley.com/doi/10.1002/pro.302601122nas a2200169 4500008004100000020001400041245009100055210006900146260001300215300001200228490000600240520059300246100002700839700001700866700002000883856004900903 2015 eng d a1867-245000aTerahertz optical measurements of correlated motions with possible allosteric function0 aTerahertz optical measurements of correlated motions with possib c2015-Jun a201-2160 v73 a

A suggested mechanism for allosteric response is the distortion of the energy landscape with agonist binding changing the protein structure's access to functional configurations. Intramolecular vibrations are indicative of the energy landscape and may have trajectories that enable functional conformational change. Here, we discuss the development of an optical method to measure the intramolecular vibrations in proteins, namely, crystal anisotropy terahertz microscopy, and the various approaches which can be used to identify the spectral data with specific structural motions.

1 aNiessen, Katherine, A.1 aXu, Mengyang1 aMarkelz, A., G. uhttps://markelz.physics.buffalo.edu/node/255