Characterization of supramolecular particles in solutions of bacterial lipopolysaccharides by dynamic light scattering and spectrofluorometry
Evgeniya V. Kuznetsova, 1 Natalya S. Velichko, 2 Gennady L. Burygin 1, 2, 3
1 Saratov State University, Saratov, Russia 2 Institute of Biochemistry and Physiology of Plants and Microorganisms FSC RAS, Saratov, Russia 3 Vavilov Saratov State University of Genetics, Biotechnology and Engineering, Saratov, Russia
Abstract
The physicochemical properties of supramolecular complexes of biomacromolecules are of decisive importance for the manifestation of their biological activity. The methods of dynamic light scattering (DLS) and fluorescence spectroscopy make it possible to relatively quickly obtain data on the structure of biopolymers and their complexes. We studied solutions of lipopolysaccharides (LPS) of seven strains of soil and plant-associated bacteria belonging to the genera Azospirillum, Herbaspirillum, and Ochrobactrum, as well as their deacylated derivatives (dLPS). The DLS method was used to measure the sizes of supramolecular complexes of the studied preparations in aqueous and buffer systems, their zeta potentials, and the relative mass-volume concentrations of biopolymers. It has been established that deacylation of LPS leads to a significant decrease in the size of micelles (2–4 times) with a multiple increase in light scattering, which can be explained by a significant increase in the mass-volume concentrations of biopolymers within supramolecular complexes. Spectrofluorimetry was used to determine the critical micelle concentrations (CMC) of the studied preparations into solutions with N-phenyl-1-naphthylamine. Comparison of CMC values for LPS and dLPS preparations showed that deacylation of LPS leads to a decrease (by 1.5–4 times) in the minimum concentration of biomacromolecules required for the formation of micelles. Thus, deacylation of LPS leads to the formation of smaller and denser micelles at lower concentrations of drugs, which can provide better bioavailability of biopolymers and increase their activity.
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Evgeniya V. Kyznetsova
Saratov State University
Russia
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