NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456, Singapore.
Nanoscale. 2016 Apr 28;8(17):9425-41. doi: 10.1039/c6nr01697a.
We investigate the molecular interactions between graphene oxide (GO) and human blood plasma proteins. To gain an insight into the bio-physico-chemical activity of GO in biological and biomedical applications, we performed a series of biophysical assays to quantify the molecular interactions between GO with different lateral size distributions and the three essential human blood plasma proteins. We elucidate the various aspects of the GO-protein interactions, particularly, the adsorption, binding kinetics and equilibrium, and conformational stability, through determination of quantitative parameters, such as GO-protein association constants, binding cooperativity, and the binding-driven protein structural changes. We demonstrate that the molecular interactions between GO and plasma proteins are significantly dependent on the lateral size distribution and mean lateral sizes of the GO nanosheets and their subtle variations may markedly influence the GO-protein interactions. Consequently, we propose the existence of size-dependent molecular interactions between GO nanosheets and plasma proteins, and importantly, the presence of specific critical mean lateral sizes of GO nanosheets in achieving very high association and fluorescence quenching efficiency of the plasma proteins. We anticipate that this work will provide a basis for the design of graphene-based and other related nanomaterials for a plethora of biological and biomedical applications.
我们研究了氧化石墨烯（GO）与人血浆蛋白之间的分子相互作用。为了深入了解 GO 在生物和生物医学应用中的生物物理化学活性，我们进行了一系列生物物理测定，以定量研究不同侧向尺寸分布的 GO 与三种基本人类血浆蛋白之间的分子相互作用。我们通过确定定量参数，如 GO-蛋白结合常数、结合协同性和结合驱动的蛋白质结构变化，阐明了 GO-蛋白相互作用的各个方面，特别是吸附、结合动力学和平衡以及构象稳定性。我们证明，GO 与血浆蛋白之间的分子相互作用显著依赖于 GO 纳米片的侧向尺寸分布和平均侧向尺寸，其微小变化可能显著影响 GO-蛋白相互作用。因此，我们提出了 GO 纳米片与血浆蛋白之间存在尺寸依赖性的分子相互作用，重要的是，在实现血浆蛋白的高结合和荧光猝灭效率方面，GO 纳米片存在特定的临界平均侧向尺寸。我们预计这项工作将为设计基于石墨烯的和其他相关纳米材料提供基础，以实现广泛的生物和生物医学应用。
