@article {559, title = {Apparatus and method for analyzing a sample }, year = {2021}, publisher = {USPTO}, address = {United States}, abstract = {
An apparatus and method for Crystal Anisotropy Terahertz Microscopy ({\textquotedblleft}CATM{\textquotedblright}) 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 ({\textquotedblleft}EO{\textquotedblright}) 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.
}, issn = {11,125,685}, url = {https://patents.google.com/patent/US11125685B2/en}, author = {Markelz, Andrea G and Acbas, Gheorghe and Niessen, Katherine A.} } @article {254, title = {Importance of Protein Vibration Directionality on Function}, journal = {Biophysical Journal}, volume = {112}, number = {3}, year = {2017}, note = {Snell, Edward/G-2055-2018
Snell, Edward/0000-0001-8714-3191
1
58th Annual Meeting of the Biophysical-Society
Feb 15-19, 2014
San Francisco, CA
Biophys Soc
}, month = {Feb 3}, pages = {353A-353A}, isbn = {0006-3495}, doi = {10.1016/j.bpj.2016.11.1916}, author = {Niessen, Katherine A. and Xu, Mengyang and Deng, Yanting and Snell, Edward H. and Markelz, Andrea G.} } @conference {546, title = {Direct Measurements of the Long-Range Collective Vibrations of Photoactive Yellow Protein}, booktitle = {30th Anniversary Symposium of The Protein Society}, year = {2016}, address = {Baltimore MD}, abstract = {

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

}, doi = {10.1002/pro.3026}, url = {https://onlinelibrary.wiley.com/doi/10.1002/pro.3026}, author = {Deng, Yanting and Xu, Mengyang and Niessen, Katherine A. and Schmidt, Marius and Markelz, Andrea G.} } @article {255, title = {Terahertz optical measurements of correlated motions with possible allosteric function}, journal = {Biophysical Reviews}, volume = {7}, number = {2}, year = {2015}, note = {19}, month = {2015-Jun}, pages = {201-216}, abstract = {

A suggested mechanism for allosteric response is the distortion of the energy landscape with agonist binding changing the protein structure{\textquoteright}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.

}, isbn = {1867-2450}, doi = {https://dx.doi.org/10.1007\%2Fs12551-015-0168-4}, author = {Niessen, Katherine A. and Xu, Mengyang and Markelz, A. G.} }