Isolation, partial characterization, and biological properties of polysaccharides from crude papain

Two polysaccharides have been isolated from crude papain by precipitation of papain with ammonium sulfate, further precipitation of other proteins with trichloroacetic acid, and chromatography of the supernatant on DEAE-cellulose. The first polysaccharide to be eluted, designated PP-I, contained D-glucuronic acid, D-glucose, D-galactose, L-arabinose, and L-rhamnose, in the approximate molar ratios of 4:1:12:10:4. The other (PP-II), eluted at a higher salt-concentration, contained the same sugars (with about one-third less glucose and more uronic acid) in the approximate molar ratios of 13:1:40:26:12. Reduction of the uronic acid groups of PP-II produced a polysaccharide (PP-II-R) containing the same sugars in the approximate molar ratios of 2:11:37:28:12. Hydrolysis of a mixture of the two polysaccharides yielded an aldobiouronic acid, D-glucosyluronic acid-D-galactose. Neither polysaccharide preparation contained protein. These polysaccharides dramatically affected aggregation and alignment of normal human fibroblasts but had no effect on a mouse embryo fibroblast aneuploid cell-line that does not exhibit contact inhibition of growth or movement. In aggregating cells, these polysaccharides caused the cells to behave as contact-inhibited cells, that is, cell division and nuclear area were decreased.