RUI: Chemically Modified Enzymes to Control Adsorption on Gold Nanoparticles for Enhanced Structure/Function

在化学系大分子、超分子和纳米化学项目的支持下，伊利诺伊州立大学的Jeremy Driskell教授正在将化学合成和先进的化学分析工具相结合，研究蛋白质如何吸附在金纳米颗粒上，并保持或增强其生物功能。这项研究确定了蛋白质和纳米颗粒之间的关键相互作用，可以利用这些相互作用来防止蛋白质展开，并促进纳米颗粒表面的受控释放。Driskell教授和他的学生正在对蛋白质进行化学修饰，以安装对金纳米颗粒具有高亲和力的化学锚，并测量被吸附的蛋白质层的稳定性和生物功能。他们的发现可能导致预测性设计参数，以形成强大和高功能的蛋白质纳米颗粒探针，并广泛影响现代生物传感、医学成像、药物输送和生物催化。该项目为本科生提供支持，让他们参与身临其境的研究体验，学习先进的分析技术，并欣赏多学科方法来解决问题。此外，Driskell博士和他支持的本科生与伊利诺伊州研究院合作，为高中生提供紧张而又有指导的研究体验。对蛋白质-纳米颗粒界面的详细了解对于缓解对吸附的蛋白质功能产生负面影响的结构变化以及利用增强蛋白质功能的稳定相互作用至关重要。蛋白质表面可接触的硫醇被认为是吸附在金纳米颗粒上并形成硬电晕的主要原因；因此，可以利用精确控制蛋白质硫醇数量的能力来优化生物偶联功能。提出了一种在一系列酶上安装硫醇官能团的合成策略。优化了反应条件，以精确控制硫醇的数量，并用高分辨率质谱仪、Zeta电位和Ellman试剂进行监测。通过纳米颗粒跟踪分析定量评估的吸附亲和力和通过竞争性蛋白质结合测量的蛋白质交换率与蛋白质呈现的表面可及硫醇的数量相关。此外，对游离和纳米颗粒固定的蛋白质的结构和功能进行了比较，以确定蛋白质硫基化与纳米颗粒吸附后的蛋白质结构/功能之间的任何关系。该项目的成功完成推动了高度活性和稳定的蛋白质-AuNP结合物的新颖设计，这是推动生物结合物启用的平台技术的关键。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Jeremy Driskell of Illinois State University is combining chemical synthesis and advanced chemical analysis tools to study how proteins adsorb onto gold nanoparticles and maintain or enhance their biological function. The study identifies key interactions between the protein and nanoparticle that can be exploited to prevent protein unfolding and to facilitate controlled release from the nanoparticle surface. Professor Driskell and his students are chemically modifying proteins to install chemical anchors with high affinity for the gold nanoparticles and measuring the stability and biological function of the adsorbed protein layer. Their discoveries could lead to predictive design parameters to form robust and highly functional protein-nanoparticle probes and broadly impact modern biosensing, medical imaging, drug delivery, and biocatalysis. This project provides support for undergraduate students to participate in an immersive research experience to learn advanced analytical techniques and gain an appreciation for a multidisciplinary approach to problem solving. Additionally, in collaboration with the Illinois Research Academy, Dr. Driskell and his supported undergraduate students provide high school students with an intense, yet supervised, research experience. A detailed understanding of the protein-nanoparticle interface is critical to mitigate structural changes that negatively impact the function of the adsorbed protein and to leverage stabilizing interactions that enhance protein function. Surface accessible thiols on a protein are hypothesized to be primarily responsible for the adsorption onto gold nanoparticles and the formation of a hard corona; thus, the ability to precisely control the number of protein thiols can be exploited to optimize bioconjugate function. A synthetic strategy is proposed to install thiol functional groups on a series of enzymes. The reaction conditions are optimized to precisely control the number of thiols, and monitored by high-resolution mass spectrometry, zeta potential, and Ellman’s reagent. Adsorption affinity, quantitatively assessed using nanoparticle tracking analysis, and protein exchange rate, measured via a competitive protein binding, is correlated with the number of surface accessible thiols presented by the protein. Additionally, the structure and function of the free and nanoparticle-immobilized protein is compared to identify any relationship between protein thiolation and protein structure/function upon adsorption to a nanoparticle. Successful completion of this project drives the novel design of highly active and stable protein-AuNP conjugates that is critically needed to advance bioconjugate-enabled platform technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.