College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; China National Engineering Research Center for Fruit and Vegetable Processing, Beijing 100083, China; Key Laboratory of Fruit and Vegetable Processing, Ministry of Agriculture, Beijing 100083, China.
Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, United States of America; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY, United States of America; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States of America.
Carbohydr Polym. 2022 Jun 1;285:119250. doi: 10.1016/j.carbpol.2022.119250. Epub 2022 Feb 15.
A pectic polysaccharide (WAP) was isolated from squash and identified as a homogalacturonan with a molecular mass of 83.2 kDa by GPC, monosaccharide composition analysis, FT-IR and NMR spectra. Sulfation modification of WAP was carried out and a sulfated derivative (SWAP) was obtained with a substitution degree of 1.81. The NMR spectrum indicated that the sulfation modification mainly occurred at the C-2 and C-3 positions of galacturonan residues. The binding pattern of SWAP to tau K18 protein was observed in 2D HN HSQC spectra of tau, which resembled the tau-heparin interaction, with R2 domain as the major binding region. These results suggest that SWAP has the potential to act as a heparin mimic to inhibit the transcellular spread of tau; thus natural polysaccharide from squash may be developed into therapies for AD and related tauopathies.
从南瓜中分离得到一种果胶多糖（WAP），通过 GPC、单糖组成分析、FT-IR 和 NMR 光谱鉴定其为相对分子质量为 83.2 kDa 的均一型半乳糖醛酸聚糖。对 WAP 进行硫酸酯化修饰，得到取代度为 1.81 的硫酸化衍生物（SWAP）。NMR 谱表明硫酸酯化修饰主要发生在半乳糖醛酸残基的 C-2 和 C-3 位。在 tau 的二维 HN HSQC 谱中观察到 SWAP 与 tau K18 蛋白的结合模式，类似于 tau-肝素相互作用，以 R2 结构域为主要结合区域。这些结果表明，SWAP 有可能作为肝素类似物抑制 tau 的细胞间传播；因此，来自南瓜的天然多糖可能被开发为 AD 和相关 tau 病的治疗方法。
