Correlation between Molecular Weight and Branch Structure of Glycopolymers Stars and Their Binding to Lectins
Correlation between Molecular Weight and Branch Structure of Glycopolymers Stars and Their Binding to Lectins
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DOI：
10.1021/ma501742v
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发表时间：
2015-01-27
期刊：
影响因子：
5.5
通讯作者：
Stenzel, Martina H.
中科院分区：
文献类型：
--
作者：
Chen, Yong;Lord, Megan S.;Stenzel, Martina H.
据推测，当两个碳水化合物单元之间的距离等于凝集素的两个结合位点时，可以实现碳水化合物的最大结合。因此，使用 RAFT 聚合制备糖星形聚合物库来研究与刀豆球蛋白 A (Con A) 的相互作用。星形聚合物的每个臂均具有嵌段结构，由作为外嵌段的聚(2-丙烯酰乙基-2',3',4',6'-四-O-乙酰基-α-d-吡喃甘露糖苷)(PMEA)和作为内嵌段的无活性但水溶性的聚(丙烯酸2-羟乙酯)(PHEA)组成。使用动态光散射确定星形聚合物的尺寸，并测量缓冲溶液中 3 至 12 nm 之间的流体动力学直径，这与两个 6.5 nm 的结合袋之间的距离相匹配 (Chem. Rev. 2002, 102, 555)。采用浊度测定、沉淀测定、表面等离子体共振和石英晶体微天平来研究聚合物与Con A的结合。发现位于星核的PHEA的分子量的影响有助于链拉伸，从而允许与更多的Con A分子相互作用。较长的 PMEA 块与较短的块相比，每个甘露糖官能团的结合效率较低。结果发现，溶液中聚合物的初始直径在决定结合效率方面不起作用。测得的每个星形聚合物缀合的 Con A 量表明，在此过程中，链显着拉伸以容纳最大量的 Con A。
It has been hypothesized that maximum binding of carbohydrates can be achieved when the distance between two carbohydrate units are equivalent to two binding sites of a lectin. Therefore, a library of glyco starpolymers was prepared using RAFT polymerization to study the interaction with Concanavalin A (Con A). The starpolymers had a block structure in each arm and were composed of poly(2-acryloylethyl-2',3',4',6'-tetra-O-acetyl-alpha-d-mannopyranoside) (PMEA) as the outer block and the inactive, but water-soluble, poly(2-hydroxyethyl acrylate) (PHEA) as the inner block. The sizes of the starpolymers were determined using dynamic light scattering and hydrodynamic diameters between 3 and 12 nm in buffer solution were measured, which match the distance between two binding pockets of 6.5 nm ( Chem. Rev. 2002, 102, 555). Turbidity assay, precipitation assay, surface plasmon resonance and quartz crystal microbalance were employed to investigate the binding of the polymers with Con A. The effect of the molecular weight of PHEA, which is located in the core of the star, was found to contribute to chain stretching allowing the interaction with more Con A molecules. Longer PMEA blocks showed a lower binding efficiency per mannose functionality than shorter blocks. It was found that the initial diameter of the polymer in solution does not play a role in determining the binding efficiency. The measured amount of Con A conjugated per star polymer suggests that during the process the chains stretch significantly to accommodate a maximum amount of Con A.