Effects of Discrete Protein-Surface Interactions in Scanning Force Microscopy Adhesion Force Measurements.
Effects of Discrete Protein-Surface Interactions in Scanning Force Microscopy Adhesion Force Measurements.
复制标题
扫描力显微镜粘附力测量中离散蛋白质-表面相互作用的影响。
DOI：
10.1021/la00004a051
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Hlady,Vladimir
中科院分区：
文献类型：
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作者：
Stuart,JoanK;Hlady,Vladimir
利用扫描力显微镜（SFM）测量探针结合配体和表面结合蛋白质之间的特异性分子识别力的潜力最近得到了广泛的关注。通常，观察到的SFM力-位移曲线的不连续性归因于离散的、特定的亲和键的断裂。本文对表面固定的抗荧光IgG分子和SFM探针结合的荧光素配体组成的分子识别系统的研究表明，SFM力-位移曲线中类似的间歇性不连续实际上可能主要是由于蛋白质和SFM探针之间的非特异性离散相互作用。讨论了本研究中使用的球形微珠系统的机械行为，因为它似乎会导致表面和探针之间的分离距离的错误指示。在粘附曲线中看到的导致“粘滑”样不连续性的强横向相互作用可能是由于蛋白质的异质性和实验系统中允许的分子流动性的缺乏而导致的局部粘附的结果。随着蛋白质和探针之间的接触时间的增加，该效果被放大。在特定的配体-蛋白质系统中可能导致这种异常行为的因素进行了讨论，以避免误解SFM粘附测量。
The potential for measuringspecific molecular recognition forces between probe-bound ligands and surface-bound proteins using a scanning force microscope (SFM) has recently gained much attention. Generally, observed discontinuities in the SFM force-displacement curves are attributed to thebreaking of discrete, specific affinity bonds. The presentstudy on the molecular recognition system composed of surface-immobilized antifluorescyl IgG molecules and SFM probe-bound fluorescein ligands has demon-strated that similar intermittent discontinuities in the SFM force-displacement curves may in fact be largely due to nonspecific discrete interactions between the protein and the SFM probe. The mechanical behavior of the cantilever-spherical bead system used in this study is discussed, as it appearsto cause a false indication of the separation distance between the surface and probe. The strong lateral interactions which result in “stick and slip”-like discontinuities seen in the adhesion curves are likely the result of localized adhesion due to the heterogeneous nature of proteins and the lack of molecular mobility allowed in the experimental system. The effect is magnified with increasing contact time between the protein and probe. Factorswhich may cause such anomalous behavior in a specific ligand—protein system are discussed in order to avoid misinterpretation of SFM adhesion measurements.