Xyloglucan from suspension-cultured soybean cells

Abstract

Two kinds of xyloglucans were obtained from the cell walls of suspension-cultured soybean cells together with an additional one from the culture medium. They had almost the same properties, i.e., sugar composition, [α]_d value, and iodine staining spectrum. The molecular weights of the two kinds of wall xyloglucans were 180,000 and 60,000, whereas that of the extracellular xyloglucan shifted from 60,000 to 30,000 with the progress of cultivation. The results from methylation analysis and fragmentation analysis with endoglucanase indicated that each xyloglucan was mainly constructed of two kinds of oligosaccharide repeating units, a heptasaccharide (glucose/xylose, 4 : 3) and a nonasaccharide (glucose/xylose/galactose/fucose, 4 : 3 : 1 : 1). Although the amount of wall xyloglucan increased during cell growth, the ratio of xyloglucan to total hemicellulose remained constant at about 50%.