Structural Study of Wheat Gliadin in Different Solvents by Spectroscopic Techniques

Physicochemical properties of gliadin in different solvents (dimethyl sulfoxide (DMSO), H2O, and aqueous ethanol) and pH (9.8, 6.8, and 1.2) were investigated using dynamic light scattering (DLS), zeta potential (ZP), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Gliadin-DMSO and gliadin-deionized water (H2O) (pH 9.8) showed a lower size distribution, whereas samples solubilized in 60% aqueous ethanol presented a lower size distribution only at pH 1.2. ZP analysis showed that gliadin-H2O (pH 9.8) was the most stable evaluated system. ZP results of gliadin-DMSO indicated an unstable system, with the coexistence of several protein conformations. ATR-FTIR analysis showed that, in H2O, most protein conformations were beta-sheets, while in DMSO a band at 1660 cm(-1) appeared to be related to protein unfolding. The techniques proved to be effective in monitoring conformation and stability of all gliadin/solvent systems. Such information can be used in the development of new gliadin-based materials.

Automated summary

The physicochemical properties of gliadin in different solvents and pH values were investigated, revealing that gliadin showed lower size distribution in certain conditions. The stability analysis showed that gliadin in H2O (pH 9.8) was the most stable system, while gliadin in DMSO was unstable. The techniques used in the study proved to be effective in monitoring the conformation and stability of all gliadin/solvent systems, providing valuable information for the development of new gliadin-based materials.