Tapping into Synchrotron and Benchtop Circular Dichroism Spectroscopy for Expanding Studies of Complex Polysaccharides and their Interactions in Anoxic Archaeological Wood

Abstract

Circular dichroism (CD) (and synchrotron circular dichroism (SCD)) spectroscopy is a rapid, highly sensitive technique used to investigate structural conformational changes in biomolecules in response to interactions with ligands in solution and in film. It is a chiroptical method and at least one of the interacting molecules must possess optical activity (or chirality). In this review, we compare the capabilities of CD and SCD in the characterisation of celluloses and lignin polymers in archaeological wood. Cellulose produces a range of spectral characteristics dependent on environment and form; many of the reported transitions occur in the vacuum-ultraviolet region (< 180 nm) most conveniently delivered using a synchrotron source. The use of induced CD in which achiral dyes are bound to celluloses to give shifted spectra in the visible region is also discussed, together with its employment to identify the handedness of the chiral twists in nanocrystalline cellulose. Lignin is one target for the design of future consolidants that interact with archaeological wood to preserve it. It is reportedly achiral, but here we review several studies in which CD spectroscopy has successfully revealed lignin interactions with chiral enzymes, highlighting the potential usefulness of the technique in future research to identify new generation consolidants.

Analytical approaches for assessing protein structure in protein-rich food: A comprehensive review

“…Circular dichroism spectroscopy (CD) includes electronic transition CD, vibration CD, fluorescence detection CD and ultraviolet CD. It is mainly used to study chiral molecules, including the recognition of secondary structures, and the study of the conformational changes in tertiary structures of biological monomers and polymer molecules, such as proteins, nucleic acids, and carbohydrates ( Phillips-Jones & Harding, 2019 ).…”

“…Mass spectrometry plays an important role in protein primary structure analysis. Moreover, some spectroscopic techniques including Fourier transform infrared spectroscopy (FTIR) ( Sazonova, Grube, Shvirksts, Galoburda, & Gramatina, 2019 ), Raman spectroscopy ( Maiti, Apetri, Zagorski, Carey, & Anderson, 2004 ), circular dichroism spectroscopy (CD) ( Phillips-Jones & Harding, 2019 ), and fluorescence spectroscopy ( Wang, Sun, Pu, & Wei, 2017 ) are simple, rapid, and have drawn significant attention for their monitoring of secondary and tertiary structure changes of proteins.…”