Purification, characterization, and modification of T lymphocyte-stimulating polysaccharide from spores of Ganoderma lucidum.
The hot-water extract of the spores of Ganoderma lucidum was shown to have a stimulating effect on concanavalin A-induced mitogenic activity of T lymphocytes. Bioassay-guided separation led to the isolation of a polysaccharide with potent T lymphocyte-stimulating activity by ethanol fractionation, anion-exchange, and size-exclusion chromatography. Based on the composition and methylation analyses, periodate oxidation, Smith degradation, and NMR spectroscopy, the native polysaccharide was shown to be a beta-D-(1-->3)-glucan with branches of terminal glucosyl residues substituted at C-6 of the glucose residues in the main chain. The branching ratio is approximately 20%. A series of sulfated or carboxymethylated derivatives were prepared and their structural features were elucidated by chemical and spectral analyses. The solution conformation and T lymphocyte proliferation effect of the glucans before and after derivatization were compared and discussed. The data obtained indicate that the introduction of ionic groups would significantly affect the original conformation of the native glucan in aqueous solution and further affect T lymphocyte-stimulating activity. The triple-helical structure of the glucans, the nature of the ionic groups, and the density of negative charge were considered to be closely related to this activity.
Bao
Xing-Feng
XF
Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, PR China.
Zhen
Yun
Y
Ruan
Li
L
Fang
Ji-Nian
JN
D000818:Animals; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D004396:Coloring Agents; D003224:Congo Red; D005260:Female; D005656:Fungal Proteins / Q000737:chemistry; D032902:Ganoderma / Q000737:chemistry*; D006868:Hydrolysis; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D051379:Mice; D008813:Mice, Inbred ICR; D008968:Molecular Conformation; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010504:Periodic Acid / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013172:Spores, Fungal / Q000737:chemistry*; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects*
D002241:Carbohydrates; D004396:Coloring Agents; D005656:Fungal Proteins; D011134:Polysaccharides; D010504:Periodic Acid; D003224:Congo Red