A glycoprotein from mountain cultivated ginseng: Insights into their chemical characteristics and intracellular antioxidant activity

A glycoprotein (MGP2) from mountain-cultivated ginseng (MCG) was purified by Tris-HCl extraction followed by DEAE-52 ion exchange chromatography and Sephadex G-100 gel filtration chromatography. The approximate molecular weight (27.0 kDa) and monomeric nature were determined by reduced and non-reduced SDS-PAGE. The structure of MGP2 was characterized by a practical and reliable "protein-polysaccharide analyzed by spectroscopy combined with chemical analysis" strategy. The results showed that MGP2 belonged to Arabinogalactan proteins (AGPs) which contained high amount of Glc (35.1 %). The hemagglutination test concluded that MGP2 was not a lectin. In addition, the MGP2 exhibited antioxidant activity by scavenging radical capacity tests and the ability to protect human erythrocytes and RAW264.7 cells from oxidative damage induced by AAPH. Therefore, these results suggested that glycoprotein MGP2 could be used as a natural antioxidant in drug and food industry.