School of Chemical and Material Engineering, State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China.
Int J Biol Macromol. 2018 Jul 15;114:1064-1070. doi: 10.1016/j.ijbiomac.2018.03.054. Epub 2018 Mar 13.
β-d-glucan (GLP20) isolated from Ganoderma lucidum fruiting bodies was successfully fractionated into five fractions with different weight-average molecular weights (M) through ultrasonic irradiation. The M, radius of gyration (R), hydrodynamic radius (R) and intrinsic viscosity ([η]) of these fractions in phosphate buffered saline (PBS) aqueous solution were determined using HPSEC-MALLS-RI-VS system. The results indicated that β-d-glucan displayed rigid chain conformations with ρ values lager than 2.06 for the five fractions. By applying the polymer solution theory, the exponent (ν and α) values of R = kM and [η] = kM were calculated as 0.72 and 1.05, respectively, which confirmed the rigid chain conformation of glucans with M from 2.9 × 10 to 2.42 × 10 g·mol. According to the known theory for chains, the molar mass per unit contour length M, persistence length q and contour length h per main-chain glucose residue were estimated to be 2150 nm, 128 nm and 0.30 nm, respectively, which indicated that the glucan existed as triple-helical chains in PBS aqueous solution. Bioactivity study of glucan fractions on lymphocytes and THP-1 macrophages demonstrated that all these fractions could stimulate lymphocyte proliferation, promote macrophages to form pseudopodia, and enhance the levels of inflammatory cytokines IL-6 and TNF-α. Meanwhile, the glucan fractions with M higher than 1.82 × 10 g·mol exhibited better activity on enhancing the release of inflammatory cytokines.
从灵芝子实体中分离得到的β-d-葡聚糖（GLP20）通过超声辐射成功地分为五个不同重均分子量（Mw）的级分。使用 HPSEC-MALLS-RI-VS 系统测定了这些级分在磷酸盐缓冲盐水（PBS）水溶液中的 Mw、回转半径（R）、流体力学半径（Rh）和特性粘数（[η]）。结果表明，β-d-葡聚糖呈现刚性链构象，五个级分的 ρ 值均大于 2.06。通过应用聚合物溶液理论，计算了 Rh=kM 和 [η]=kM 的指数（ν 和 α）值分别为 0.72 和 1.05，这证实了 Mw 从 2.9×10 到 2.42×10 g·mol 的葡聚糖具有刚性链构象。根据已知的链理论，单位轮廓长度的摩尔质量 M、持久长度 q 和主链葡萄糖残基的轮廓长度 h 分别估计为 2150 nm、128 nm 和 0.30 nm，这表明葡聚糖在 PBS 水溶液中存在于三螺旋链中。葡聚糖级分对淋巴细胞和 THP-1 巨噬细胞的生物活性研究表明，所有这些级分都能刺激淋巴细胞增殖，促进巨噬细胞形成伪足，并增强炎症细胞因子 IL-6 和 TNF-α的水平。同时，Mw 高于 1.82×10 g·mol 的葡聚糖级分在增强炎症细胞因子的释放方面表现出更好的活性。
