FT-IR study of the Chara corallina cell wall under deformation.

Fourier-transform infrared (FT-IR) microspectroscopy was used to investigate both the chemical composition of, and the effects of an applied strain on, the structure of the Chara corallina cell wall. The inner layers of the cell wall are known to have a transverse cellulose orientation with a gradient through the thickness to longitudinal orientation in the older layers. In both the native state and following the removal of various biopolymers by a sequential extraction infrared dichroism was used to examine the orientation of different biopolymers in cell-wall samples subjected to longitudinal strain.

Molecular interactions in bacterial cellulose composites studied by 1D FT-IR and dynamic 2D FT-IR spectroscopy.

Specific strain-induced orientation and interactions in three Acetobacter cellulose composites: cellulose (C), cellulose/pectin (CP) and cellulose/xyloglucan (CXG) were characterized by FT-IR and dynamic 2D FT-IR spectroscopies. On the molecular level, the reorientation of the cellulose fibrils occurred in the direction of the applied mechanical strain. The cellulose-network reorientation depends on the composition of the matrix, including the water content, which lubricates the motion of macromolecules in the network.

The mechanical properties and molecular dynamics of plant cell wall polysaccharides studied by Fourier-transform infrared spectroscopy.

Polarized one- and two-dimensional infrared spectra were obtained from the epidermis of onion (Allium cepa) under hydrated and mechanically stressed conditions. By Fourier-transform infrared microspectroscopy, the orientation of macromolecules in single cell walls was determined. Cellulose and pectin exhibited little orientation in native epidermal cell walls, but when a mechanical stress was placed on the tissue these molecules showed distinct reorientation as the cells were elongated.

The glycoprotein character of multiple forms of Aspergillus polygalacturonase.

Comparisons of known primary structures of polygalacturonases show that extent and localization of potential N-glycosylation sites differ. Some sites are similar in position and adjacent to strictly conserved residues at the potential active site. The presence of N-acetylglucosamine and mannose in the molecules of two homogeneous, major Aspergillus sp.

FTIR and laser-Raman spectra of oligosaccharides in water: characterization of the glycosidic bond.

Changes in conformation of oligosaccharides, and the constraints imposed by hydrogen bonding with the solvent, were studied by means of vibrational spectroscopy (FTIR-ATR and laser-Raman). Oligosaccharides differing in positions of the glycosidic bond, such as trehalose, sucrose, maltose, melibiose, lactose, maltotriose, raffinose, and stachyose, were investigated. FTIR spectra of oligosaccharides in aqueous solution at different concentrations allow differentiation of these molecules according to the types of glycosidic bonds present and the changes in conformation of their constituent monosaccharides.