Three-dimensional Raman spectroscopic imaging of protein crystals deposited on a nanodroplet

Abstract

Confocal Raman spectroscopic imaging has been used to find the location of protein crystals deposited in a nanodroplet. The depth of the protein crystal has been clearly identified by comparing the three-dimensional Raman spectroscopic images of the protein with those of water. Additionally, the low concentration region around a growing protein crystal in the nanodroplet was visualized using two-dimensional Raman spectroscopic imaging.

Raman spectroscopy of proteins: a review

“…Several Raman bands assigned to TMT are seen at 896, 938, 1004, 1034, 1127, 1450 and 1668 cm −1 in the low wavenumber region and at 2937 cm −1 in the higher range . For all three lines, TMT Raman spectra have similar profiles apart from intensities ratio of CH 2 deformation band (~1342 cm −1 ) and amide III band (~1242 cm −1 , 488 nm).…”

“…[81] Several Raman bands assigned to TMT are seen at 896, 938, 1004, 1034, 1127, 1450 and 1668 cm À1 in the low wavenumber region and at 2937 cm À1 in the higher range. [82] For all three lines, TMT Raman spectra have similar profiles apart from intensities ratio of CH 2 deformation band (~1342 cm À1 ) and amide III band (~1242 cm À1 , 488 nm). Raman spectrum of TMT has significantly better signal-to-noise ratio for 488 nm excitation and more information can be obtained from the spectral region below 800 cm À1 (e.g.…”

Identifying, studying and making good use of macromolecular crystals

“…The precise three-dimensional position of crystals in a crystallization drop has been studied using Raman spectroscopy by Nitahara et al (2012). Raman spectroscopy measures shifts in the incident wavelength caused by vibrations, phonons or other excitations in the system under study.…”

Microfluidic Approaches for Protein Crystal Structure Analysis

“…We have analyzed protein crystallization behavior in the microdroplet by theoretical and experimental approaches. 25,40,45 Spherical microdroplets with different diameters (130, 200, 360, and 500 μm) were prepared to evaluate the effect of protein molecular diffusion on the crystallization behavior. When we used a small size droplet, one protein crystal formed in the droplet, as shown in Table 1.…”

“…45 Microdroplets containing appropriate concentrations of thaumatin and precipitant were prepared by using a microfluidic device, and were collected in a PFA capillary. The capillary was placed in the sample stage.…”