Duncan Gregg A, Bevan Michael A
Chemical & Biomolecular Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States.
Langmuir. 2014 Dec 23;30(50):15253-60. doi: 10.1021/la503772g. Epub 2014 Dec 11.
Measurements and models are reported for Concanavalin A (ConA) mediated aggregation of dextran coated colloids that is tunable via a competing ConA-glucose interaction. Video and confocal scanning laser microscopy were used to characterize ConA adsorption to dextran colloids and quasi-2D dextran coated colloid aggregation kinetics vs [ConA] and [glucose]. ConA adsorption to, and aggregation rates of, dextran coated colloids increased from negligible values to high coverage and rapid rates for increasing [ConA] in the range 0.1-10 mM and decreasing [glucose] in the range 1-100 mM, consistent with dissociation constant estimates. Analysis of colloidal aggregation kinetics indicates ConA bridge formation is the rate-limiting step controlling the transition from slow to rapid aggregation. Our findings reveal a mechanism for tuning colloidal interactions and aggregation kinetics through specific, competitive biomolecular interactions, which lends insights into aggregation phenomena in mixed synthetic-biomaterial and biological systems.
报道了伴刀豆球蛋白A（ConA）介导的葡聚糖包被胶体聚集的测量结果和模型，这种聚集可通过竞争性的ConA-葡萄糖相互作用进行调节。使用视频和共聚焦扫描激光显微镜来表征ConA对葡聚糖胶体的吸附以及准二维葡聚糖包被胶体聚集动力学与[ConA]和[葡萄糖]的关系。对于0.1 - 10 mM范围内[ConA]的增加以及1 - 100 mM范围内[葡萄糖]的降低，ConA对葡聚糖包被胶体的吸附以及聚集速率从可忽略不计的值增加到高覆盖率和快速速率，这与解离常数估计值一致。胶体聚集动力学分析表明，ConA桥的形成是控制从缓慢聚集到快速聚集转变的限速步骤。我们的研究结果揭示了一种通过特定的竞争性生物分子相互作用来调节胶体相互作用和聚集动力学的机制，这为深入了解混合合成生物材料和生物系统中的聚集现象提供了见解。
