Liu Pei, Chen Liwei, Toh Jerry K C, Ang Yi Li, Jee Joo-Eun, Lim Jaehong, Lee Su Seong, Lee Song-Gil
Institute of Bioengineering and Nanotechnology , 31 Biopolis Way, The Nanos , Singapore 138669 , Singapore . Email:
Chem Sci. 2015 Jan 1;6(1):450-456. doi: 10.1039/c4sc02553a. Epub 2014 Oct 15.
The challenges inherent in the synthesis of large glycosaminoglycan (GAG) polysaccharides have made chemically accessible multivalent glycoligands a valuable tool in the field of GAG mimetics. However, the difficulty of positioning sulfated sugar motifs at desired sites has hindered efforts to precisely tailor their biofunctions. Here, we achieved precise orientation of sulfated disaccharide motifs by taking advantage of a structurally well-defined polyproline scaffold, and describe systematic explorations into the importance of the spatial arrangement of sulfated sugars along the scaffold backbone in designing multivalent glycoligands. Our protein binding studies demonstrate that the specific conformational display of pendant sugars is central to direct their multivalent interactions with NGF. By employing computational modeling and cellular studies, we have further applied this approach to engineer NGF-mediated signaling by regulating the NGF/TrkA complexation process, leading to enhanced neuronal differentiation and neurite outgrowth of PC12 cells. Our findings offer a promising strategy for the pinpoint engineering of GAG-mediated biological processes and a novel method of designing new therapeutic agents that are highly specific to GAG-associated disease.
大糖胺聚糖(GAG)多糖合成中固有的挑战使得化学上可及的多价糖配体成为GAG模拟物领域的一种有价值的工具。然而,将硫酸化糖基序定位在所需位点的困难阻碍了精确调整其生物功能的努力。在这里,我们利用结构明确的聚脯氨酸支架实现了硫酸化二糖基序的精确取向,并描述了在设计多价糖配体时对硫酸化糖沿支架主链的空间排列重要性的系统探索。我们的蛋白质结合研究表明,侧链糖的特定构象展示对于指导它们与NGF的多价相互作用至关重要。通过采用计算建模和细胞研究,我们进一步应用这种方法通过调节NGF/TrkA络合过程来设计NGF介导的信号传导,从而导致PC12细胞的神经元分化增强和神经突生长。我们的发现为精确设计GAG介导的生物过程提供了一种有前景的策略,以及一种设计对GAG相关疾病具有高度特异性的新型治疗剂的新方法。