Crystal Anisotropy Terahertz Microscopy for Protein Vibration Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current terahertz spectroscopic techniques fail to isolate specific protein intramolecular vibrations due to a dense solvent background, making it challenging to measure long-range vibrational motions critical for protein function under physiological conditions.
Innovation Solution
The Crystal Anisotropy Terahertz Microscopy (CATM) technique uses near-field THz microscopy and polarization-dependent measurements to isolate protein intramolecular vibrations by aligning protein molecules in crystals, removing the solvent background and allowing for the detection of collective modes at room temperature and full hydration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If standard THz spectroscopic techniques are used to measure protein vibrations, then the measurement can be performed, but the solvent background from librational motions obscures the protein intramolecular vibrations
Solution Approach 1:
The patent extracts the harmful solvent background signal from the measurement by using polarization-dependent spectroscopy. By measuring the difference in absorption between parallel and perpendicular polarizations, the technique isolates the protein intramolecular vibrations from the solvent librational background, enabling precise measurement of protein vibrations in hydrated crystals.
Solution Approach 2:
The patent exploits the anisotropic nature of protein crystals, where molecules are arranged in a specific orientation. This asymmetry in molecular arrangement creates polarization-dependent absorption characteristics that allow the protein vibrations to be distinguished from the isotropic solvent background, resolving the obscuration problem.
2Measurement precision
If protein crystals are used to align molecules for vibration measurement, then polarization-dependent measurements can be made, but the crystals are much smaller than the diffraction limited spot size
Solution Approach 1:
The patent replaces far-field optical spectroscopy with near-field scanning THz microscopy. This substitution allows measurement of the small crystal samples without being limited by diffraction, as the near-field technique can resolve features smaller than the wavelength of THz radiation, enabling precise measurement of vibrations in micro-sized crystals.
3Device complexity
If optical measurements are used to select modes with strong dipole coupling, then the vibrational density of states complexity is reduced, but the solvent background remains problematic
Solution Approach 1:
The patent uses polarization-dependent measurements to exploit the asymmetric orientation of protein molecules in crystals. By measuring absorption at different polarization angles, the technique selectively enhances protein vibrational modes with strong dipole coupling while the isotropic solvent background remains unchanged, allowing separation of the two signals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
CATM effectively measures protein intramolecular vibrations, providing transformative insights into the role of long-range motions in protein function and allosteric control, with distinct vibrational resonances observed even under physiological conditions.
Implementation Method 1
The strength of the absorption for a vibrational mode depends on the relative direction of the vibration transition dipole and the light polarization
Implementation Method 2
CATM is based on the insight that the local motions giving rise to the background can be isolated from the collective modes through the polarization dependence
Implementation Method 3
The presently-disclosed technique overcomes this issue by using a near-field THz microscopy method referred to herein as crystal anisotropy terahertz microscopy (CATM)
Implementation Method 4
standard THz spectroscopic techniques have been unsuccessful in isolating specific modes because of a large additional glass-like background from librational motions of the solvent
Data Source
AI summary
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.