Lyu Yanchao, Martínez Álvaro, D'Incà Federica, Mancin Fabrizio, Scrimin Paolo
Department of Chemical Sciences, University of Padova, via Marzolo, 1, 35131 Padova, Italy.
Nanomaterials (Basel). 2021 Jun 13;11(6):1559. doi: 10.3390/nano11061559.
The biotin-avidin interaction is used as a binding tool for the conjugation of biomolecules for more diverse applications; these include nanoparticle conjugation. Despite this, a thorough investigation on the different aggregates that may result from the interaction of biotinylated nanoparticles (gold nanoparticles, AuNPs, in this work) with avidin has not been carried out so far. In this paper, we address this problem and show the type of aggregates formed under thermodynamic and kinetic control by varying the biotinylated AuNP/avidin ratio and the order of addition of the two partners. The analysis was performed by also addressing the amount of protein able to interact with the AuNPs surface and is fully supported by the TEM images collected for the different samples and the shift of the surface plasmon resonance band. We show that the percentage of saturation depends on the size of the nanoparticles, and larger nanoparticles (19 nm in diameter) manage to accommodate a relatively larger amount of avidins than smaller ones (11 nm). The AuNPs are isolated or form small clusters (mostly dimers or trimers) when a large excess or a very low amount of avidin is present, respectively, or form large clusters at stoichiometric concentration of the protein. Daisy-like systems are formed under kinetic control conditions when nanoparticles first covered with the protein are treated with a second batch of biotinylated ones but devoid of avidin.
生物素-抗生物素蛋白相互作用被用作一种结合工具，用于生物分子的缀合，以实现更多样化的应用；这些应用包括纳米颗粒缀合。尽管如此，到目前为止，尚未对生物素化纳米颗粒（在本工作中为金纳米颗粒，AuNPs）与抗生物素蛋白相互作用可能产生的不同聚集体进行全面研究。在本文中，我们解决了这个问题，并通过改变生物素化AuNP/抗生物素蛋白的比例以及两种成分的添加顺序，展示了在热力学和动力学控制下形成的聚集体类型。分析还通过研究能够与AuNPs表面相互作用的蛋白量来进行，并且得到了为不同样品收集的透射电子显微镜（TEM）图像以及表面等离子体共振带的位移的充分支持。我们表明，饱和百分比取决于纳米颗粒的大小，较大的纳米颗粒（直径19 nm）比较小的纳米颗粒（11 nm）能够容纳相对更多的抗生物素蛋白。当分别存在大量过量或非常少量的抗生物素蛋白时，AuNPs分别处于孤立状态或形成小簇（主要是二聚体或三聚体），或者在蛋白的化学计量浓度下形成大簇。当首先用蛋白覆盖的纳米颗粒用第二批不含抗生物素蛋白的生物素化纳米颗粒处理时，在动力学控制条件下会形成类似雏菊的系统。
