摘要
肝素(HP)和硫酸乙酰肝素(HS)是一种高度柔性的直链多糖[1],其基本结构单元由交替重复的二糖组成,通常包含一种己糖胺(如N-乙酰-D-葡萄糖胺,GlcNAc)和一种糖醛酸(如D-葡萄糖醛酸,GlcA)[2].值得注意的是,HP/HS中普遍存在多样的磺酸化修饰,包括GlcNAc的N-磺酸化、GlcA的2-O-磺酸化以及GlcNAc的6-O-磺酸化[3].这些修饰赋予了HP/HS高度负电性,因而在与金属离子结合时,不同链段负电荷的空间排列可导致多种局部构象,甚至同一金属离子也可能结合于不同位点,使其能够与多种蛋白质发生特异性相互作用,从而在细胞生长[4]、炎症反应[5]和肿瘤抑制[6]等过程中发挥关键作用.因此,揭示HP/HS与不同金属离子的相互作用机制,对于深入理解其生物学功能具有重要意义[7~9].
Heparin(HP)and heparan sulfate(HS)are highly anionic glycosaminoglycans that play essential roles in diverse biological processes through the metal ion-mediated interactions with proteins.However,direct characteriza⁃tion of HS-metal ion interactions at the single-molecule level in solution remains challenging.Nanopore electrochemis⁃try is a label-free and single-molecule technique that enables direct analysis of individual molecular interactions.In this study,a T 232 K/K 238 Q Aerolysin nanopore featuring an enhanced electrostatic repelling barrier was utilized to probe the interactions between HS and different metal ions.By systematically varying the electrolyte cations(Na+,K+,and Ca 2+),we have found that the metal ions significantly regulate HS translocation behavior by modulating its conformation,charge screening,and HS-nanopore interactions.Notably,in addition to Ca 2+,which exhibits strong binding affinity to HS,the monovalent cations Na⁺and K⁺with similar physicochemical properties and weaker binding also induce distinct single-molecule signal signatures.Our results demonstrate that the nanopore-based single-molecule analysis holds strong potential to resolve the fine structural features of HS,enabling the characteriza⁃tion of sulfation site distributions,repeat-unit lengths,and related sequence features,and thereby providing a new avenue for high-resolution analysis of complex glycans.
作者
张鹏玲
高凡
陈嘉乐
邹爱华
汤娟
马慧
蒋翠玲
万永菁
夏冰清
李铁海
高召兵
应佚伦
龙亿涛
ZHANG Pengling;GAO Fan;CHEN Jiale;ZOU Aihua;TANG Juan;MA Hui;JIANG Cuiling;WAN Yongjing;XIA Bingqing;LI Tiehai;GAO Zhaobing;YING Yilun;LONG Yitao(College of Chemistry and Materials Science,Shanghai Normal University,Shanghai 200234;Molecular Sensing and Imaging Center,School of Chemistry,Nanjing University,Nanjing 210023;College of Chemistry and Materials,Jiangxi Normal University,Nanchang 330022;School of Chemistry and Chemical Engineering,Zhejiang Sci⁃Tech University,Hangzhou 310018;School of Information Science and Engineering,East China University of Science and Technology,Shanghai 200237;Shanghai Institute of Materia Medica,Chinese Academy of Sciences,Shanghai 201203)
出处
《高等学校化学学报》
北大核心
2026年第2期1-6,共6页
Chemical Journal of Chinese Universities
基金
上海市市级科技重大专项项目
国家自然科学基金(批准号:32250019,22474055)
中央高校基本科研业务费专项资金(批准号:020514380356)资助。
