Isolation of protein-polysaccharide conjugates from Solanum tuberosum L. rootlets by extended reversed-phase flash chromatography

Abstract

Polysaccharides and their conjugates with various biologically active compounds (proteins, nucleic acids, peptides etc.) are of great importance, they take a part in various biological processes. The one of the important feature of polysaccharides is possibility to form wide variety of branched structures with different molecular masses and, thus, they can form very complicated structural conjugates with wide range of biologically active compounds. Cells of tubers of cultivated potato (Solanum tuberosum L.) contain high amounts of polysaccharides conjugated with proteins and nucleotides. In this work we developed fast and efficient chromatographic procedure for the isolation of protein-polysaccharide conjugates from the rootlets of Solanum tuberosum L. It consisted of double-cartridge flash-chromatographic system, filled with the cross-linked macroporous styrene-divinylbenzene and C18 stationary phases. Isolated products were characterized by different analytical methods, including HPLC (reversed phase and size exclusion chromatography), gas chromatography and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) (determination of proteins). Some structural features were determined by means of IR spectroscopy in the region characteristic for saccharides (1250-750 cm^-1). It could be concluded, that isolated conjugates consisted of arabinogalactane polysaccharide and protein with average MM 60 kDa. Analytical data obtained for both products, isolated using conventional precipitation method and flash-chromatographic procedure were similar.