Force spectroscopy of the double-tethered concanavalin-A mannose bond
Force spectroscopy of the double-tethered concanavalin-A mannose bond
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DOI：
10.1016/s0006-3495(04)74299-x
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发表时间：
2004-04-01
影响因子：
3.4
通讯作者：
McElfresh, MW
中科院分区：
文献类型：
--
作者：
Ratto, TV;Langry, KC;McElfresh, MW
我们提出的测量所需的力断裂一个单一的蛋白质-糖键使用的方法，提供特异性和非特异性结合事件之间的选择性歧视，并有助于验证原子力显微镜尖端上的单个功能分子的存在。特别地，在键加载速率类似于10 nN/s时，聚合物栓系的伴刀豆球蛋白-A蛋白（ConA）和类似栓系的甘露糖碳水化合物之间的相互作用力测量为47 +/- 9 pN。使用聚合物分子构型的计算机模拟来确定聚合物在结合期间可以扫出的角度，并且结合质谱法，用于将角度效应与由于系链长度分布引起的效应分开。我们发现，当使用市售的聚合物系绳的长度从19到29 nm的变化，角度的影响是相对较小的断裂分布是由10 nm宽度的系绳长度分布为主。总之，我们表明，拴系蛋白质及其配体允许确定具有高灵敏度的单分子键断裂力，并包括一些验证原子力显微镜尖端上的单拴系功能分子的存在。
We present the measurement of the force required to rupture a single protein-sugar bond using a methodology that provides selective discrimination between specific and nonspecific binding events and helps verify the presence of a single functional molecule on the atomic force microscopy tip. In particular, the interaction force between a polymer-tethered concanavalin-A protein (ConA) and a similarly tethered mannose carbohydrate was measured as 47 +/- 9 pN at a bond loading rate of similar to10 nN/s. Computer simulations of the polymer molecular configurations were used to determine the angles that the polymers could sweep out during binding and, in conjunction with mass spectrometry, used to separate the angular effects from the effects due to a distribution of tether lengths. We find that when using commercially available polymer tethers that vary in length from 19 to 29 nm, the angular effects are relatively small and the rupture distributions are dominated by the 10-nm width of the tether length distribution. In all, we show that tethering both a protein and its ligand allows for the determination of the single-molecule bond rupture force with high sensitivity and includes some validation for the presence of a single-tethered functional molecule on the atomic force microscopy tip.