Role of Free Thiol on Protein Adsorption to Gold Nanoparticles
Role of Free Thiol on Protein Adsorption to Gold Nanoparticles
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DOI：
10.1021/acs.langmuir.0c01550
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发表时间：
2020-08-11
期刊：
影响因子：
3.9
通讯作者：
Driskell, Jeremy D.
中科院分区：
文献类型：
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作者：
Awotunde, Olatunde;Okyem, Samuel;Driskell, Jeremy D.
蛋白质-金纳米粒子（AuNP）生物复合物在纳米医学领域有着广泛的应用前景。对蛋白质和AuNP之间的相互作用的透彻理解对于工程化这些具有期望性质的功能性生物缀合物至关重要。在这项工作中，我们研究了蛋白质-金纳米粒子缀合物的稳定性上的蛋白质所呈现的游离巯基的作用。用2-亚氨基硫杂环戊烷（鳟鱼试剂）修饰人血清白蛋白（HSA），以在蛋白质表面上引入额外的硫醇，并通过控制化学修饰剂的摩尔过量来合成HSA的三种变体，以呈现1，5和20个游离硫醇。使用这些HSA种类和表现出10个游离巯基的IgG抗体对AuNP进行蛋白质交换研究。合成抗体-AuNP缀合物，纯化并分散在含有每种HSA物质的溶液中。没有检测到蛋白质交换与HSA或修饰的HSA含有5个巯基，然而，85%的抗体被置换的AuNP表面上的广泛硫醇化的HSA提出20个游离巯基。此外，蛋白质吸附序列的影响进行了探测，其中每个HSA物种被预吸附到AuNP上，并分散在抗体溶液中。该抗体在3小时内用来自AuNP的单个硫醇完全置换HSA，需要24小时才能完全置换含有5个硫醇的修饰的HSA，并且不能置换含有20个硫醇的修饰的HSA。这些结果表明，Au-S相互作用的数量控制蛋白质和AuNP之间的结合相互作用。这项工作提供了对蛋白质-AuNP结合机制的进一步了解，并确定了工程蛋白质优化生物缀合物的重要设计原则。
Protein-gold nanoparticle (AuNP) bioconjugates have many potential applications in nanomedicine. A thorough understanding of the interaction between the protein and the AuNP is critical to engineering these functional bioconjugates with desirable properties. In this work, we investigate the role of free thiols presented by the protein on the stability of the protein-AuNP conjugate. Human serum albumin (HSA) was modified with 2-iminothiolane (Trout's reagent) to introduce additional thiols onto the protein surface, and three variants of HSA were synthesized to present 1, 5, and 20 free thiols by controlling the molar excess of the chemical modifier. Protein exchange studies on AuNPs were conducted using these HSA species and an IgG antibody which exhibited 10 free thiols. Antibody-AuNP conjugates were synthesized, purified, and dispersed in solutions containing each of the HSA species. No protein exchange was detected with the HSA or modified HSA containing 5 thiols; however, 85% of the antibody was displaced on the AuNP surface by the extensively thiolated HSA presenting 20 free thiols. Furthermore, the impact of the protein adsorption sequence was probed in which each of the HSA species were preadsorbed onto the AuNP and dispersed in a solution of antibody. The antibody fully displaced the HSA with a single thiol from the AuNP within 3 h, required 24 h to completely displace the modified HSA containing 5 thiols, and was unable to displace the modified HSA containing 20 thiols. These results indicate that the number of Au-S interactions governs the binding interaction between the protein and the AuNP. This work provides further insight into the protein-AuNP binding mechanism and identifies important design principles for engineered proteins to optimize bioconjugates.