Pan Ying, Sun Huifang, Gu Xi, Li Sujuan, Yang Shengtao, Zhang Liang, Mao Hui, Wang Pin, Yang Shasha, Yin Ronghua, Zuo Zhili, Zhao Jinhua
School of Chemistry and Materials Science, South-Central Minzu University, Wuhan 430074, China; School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China.
School of Chemistry and Materials Science, South-Central Minzu University, Wuhan 430074, China; School of Pharmaceutical Sciences, South-Central Minzu University, Wuhan 430074, China.
Carbohydr Polym. 2025 Mar 1;351:123145. doi: 10.1016/j.carbpol.2024.123145. Epub 2024 Dec 12.
Fucosylated chondroitin sulfate (FCS) from Holothuria mexicana (FCS) was selected for investigation because of its intriguing branch features. Selective β-eliminative depolymerization and the bottom-up assembly were performed to unravel that FCS consisted of a {D-GlcA-β1,3-D-GalNAc} backbone and branches of alternating Fuc (55 %) and D-GalNAc-α1,2-L-Fuc (45 %), the highest proportion of disaccharide branch reported to date. In branches, sulfation could occur at every free -OH site except O-3 of GalNAc, being the most complex and various structure features of natural FCS. Detailed structure-activity relationship analyses showed that FCS and its depolymerized products (>8 kDa) effectively competed with SLe and PSGL-1 to bind with P-sel at nano-molar level and the inhibition potency increased with Mw increasing. For the structural trisaccharide unit, di-O-sulfation of the Fuc (Fuc and Fuc) was almost 10-fold more potent than mono-O-sulfation (Fuc). Unexpectedly, higher sulfation of the disaccharide-branched tetrasaccharide unit reduced inhibition. The reversal may attribute to fewer interactions with P-sel by molecular docking study. These results suggested that the specific configuration underpinned the potent inhibition, whereas the size and sulfate number of branches were not the key factors for the specific binding. dHmF4 (8.0 kDa) potently blocked the platelet-leukocyte aggregates formation, further verifying the potential value in use.
由于墨西哥海参的岩藻糖基化硫酸软骨素（FCS）具有引人关注的分支特征，因此被选作研究对象。通过选择性β-消除解聚和自下而上的组装方法，揭示了FCS由{D-GlcA-β1,3-D-GalNAc}主链以及交替排列的岩藻糖（55%）和D-GalNAc-α1,2-L-岩藻糖（45%）分支组成，这是迄今为止报道的二糖分支比例最高的情况。在分支中，除了GalNAc的O-3位外，每个游离-OH位点都可能发生硫酸化，这是天然FCS最复杂多样的结构特征。详细的构效关系分析表明，FCS及其解聚产物（>8 kDa）能在纳摩尔水平上与SLe和PSGL-1有效竞争结合P-选择素，且抑制效力随分子量增加而增强。对于结构三糖单元，岩藻糖的二-O-硫酸化（Fuc和Fuc）的效力几乎比单-O-硫酸化（Fuc）高10倍。出乎意料的是，二糖分支四糖单元的更高硫酸化程度反而降低了抑制作用。通过分子对接研究，这种反转可能归因于与P-选择素的相互作用减少。这些结果表明，特定的构型是强效抑制作用的基础，而分支的大小和硫酸根数量不是特异性结合的关键因素。dHmF4（8.0 kDa）能有效阻断血小板-白细胞聚集体的形成，进一步验证了其潜在应用价值。
