Peptide Adsorption on Silica Nanoparticles: Evidence of Hydrophobic Interactions
Peptide Adsorption on Silica Nanoparticles: Evidence of Hydrophobic Interactions
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DOI：
10.1021/nn301866q
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发表时间：
2012-07-01
期刊：
影响因子：
17.1
通讯作者：
Perry, Carole C.
中科院分区：
文献类型：
--
作者：
Puddu, Valeria;Perry, Carole C.
生物分子和无机材料之间的界面处的分子识别和相互作用决定了重要的现象，例如蛋白质吸附、细胞粘附到生物材料或生物传感器的选择性响应。在生物分子-无机界面发生的事件，尽管它们的重要性，仍然知之甚少，从而限制了界面特性和响应的控制。在这方面的贡献，使用良好表征的二氧化硅纳米粒子和一系列肽具有异质性的物理化学性质（S1：KLPGWSG，S2：AFILPTG，和S3：LDHSLHS）确定从生物淘选对相同的颗粒，我们确定的驱动力，管理肽二氧化硅结合。通过荧光测定法在不同pH条件下获得的结合等温线使我们能够证明结合环境（pH）对给定肽表面二氧化硅纳米颗粒的吸附行为的影响。我们的实验数据表明，导致在二氧化硅上形成多层的多步吸附机制，其中主要的相互作用（即，静电或疏水/氢键合）以及它们对结合事件的相对贡献由肽本身的特性、底物的表面功能性我们的研究显示了如何通过改变表面性质，或者更简单地说，绑定环境。此外，数据揭示了在生物淘选方案中使用的洗脱条件下对带正电荷的序列的固有偏差，其中关于强结合物序列多样性的许多信息在淘选期间丢失。
Molecular recognition and interactions at the interface between biomolecules and inorganic materials determine important phenomena such as protein adsorption, cell adhesion to biomaterials, or the selective response of biosensors. Events occurring at the biomolecule-inorganic interface, despite their importance, are still poorly understood, thus limiting control of interfacial properties and response. In this contribution, using well-characterized silica nanoparticles and a series of peptides having heterogeneous physicochemical properties (S1: KLPGWSG, S2: AFILPTG, and S3: LDHSLHS) identified from biopanning against the same particles, we identify the driving forces that govern peptide silica binding. Binding isotherms obtained by fluorimetric assay under different pH conditions allowed us to demonstrate the impact of binding environment (pH) on adsorption behavior of a given peptide surface silica nanoparticle. Our experimental data suggest a multistep adsorption mechanism leading to the formation of multilayers on silica, in which the prevailing interactions (i.e., electrostatic or hydrophobic/hydrogen bonding) and their relative contribution to the binding event are governed by the identity of the peptide itself, the substrate's surface functionality (hydrophilic or hydrophobic), and the peptide bulk concentration and solution bulk pH. Our studies show how it is possible to modulate peptide uptake on silica, or in fact on any particle, by changing either the surface properties or, more simply, the binding environment. In addition, the data reveal an intrinsic bias toward positively charged sequences in the elution conditions used in the biopanning protocol with much information about strong binder sequence diversity being lost during panning.