Wang Yong, Ni Yongnian
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Chemistry, Nanchang University, Nanchang 330031, Jiangxi, China.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; Department of Chemistry, Nanchang University, Nanchang 330031, Jiangxi, China.
Talanta. 2014 Feb;119:320-30. doi: 10.1016/j.talanta.2013.11.026. Epub 2013 Nov 13.
Study of the interactions between proteins and nanomaterials is of great importance for understanding of protein nanoconjugate. In this work, we choose human serum albumin (HSA) and citrate-capped gold nanoparticles (AuNPs) as a model of protein and nanomaterial, and combine UV-vis spectroscopy with multivariate curve resolution by an alternating least squares (MCR-ALS) algorithm to present a new and efficient method for comparatively comprehensive study of evolution of protein nanoconjugate. UV-vis spectroscopy coupled with MCR-ALS allows qualitative and quantitative extraction of the distribution diagrams, spectra and kinetic profiles of absorbing pure species (AuNPs and AuNPs-HSA conjugate are herein identified) and undetectable species (HSA) from spectral data. The response profiles recovered are converted into the desired thermodynamic, kinetic and structural parameters describing the protein nanoconjugate evolution. Analysis of these parameters for the system gives evidence that HSA molecules are very likely to be attached to AuNPs surface predominantly as a flat monolayer to form a stable AuNPs-HSA conjugate with a core-shell structure, and the binding process takes place mainly through electrostatic and hydrogen-bond interactions between the positively amino acid residues of HSA and the negatively carboxyl group of citrate on AuNPs surface. The results obtained are verified by transmission electron microscopy, zeta potential, circular dichroism spectroscopy and Fourier transform infrared spectroscopy, showing the potential of UV-vis spectroscopy for study of evolution of protein nanoconjugate. In parallel, concentration evolutions of pure species resolved by MCR-ALS are used to construct a sensitive spectroscopic biosensor for HSA with a linear range from 1.8 nM to 28.1 nM and a detection limit of 0.8 nM.
研究蛋白质与纳米材料之间的相互作用对于理解蛋白质纳米缀合物至关重要。在本工作中，我们选择人血清白蛋白（HSA）和柠檬酸盐包覆的金纳米颗粒（AuNPs）作为蛋白质和纳米材料的模型，并将紫外可见光谱与交替最小二乘法的多元曲线分辨（MCR-ALS）算法相结合，提出一种新的高效方法，用于对蛋白质纳米缀合物的演化进行较为全面的研究。紫外可见光谱与MCR-ALS相结合，能够从光谱数据中定性和定量地提取吸收纯物质（本文鉴定为AuNPs和AuNPs-HSA缀合物）和不可检测物质（HSA）的分布图、光谱和动力学谱。恢复的响应谱被转换为描述蛋白质纳米缀合物演化的所需热力学、动力学和结构参数。对该系统这些参数的分析表明，HSA分子很可能主要以扁平单层的形式附着在AuNPs表面，形成具有核壳结构的稳定AuNPs-HSA缀合物，且结合过程主要通过HSA带正电的氨基酸残基与AuNPs表面柠檬酸盐带负电的羧基之间的静电和氢键相互作用发生。通过透射电子显微镜、zeta电位、圆二色光谱和傅里叶变换红外光谱对所得结果进行了验证，显示了紫外可见光谱在研究蛋白质纳米缀合物演化方面的潜力。同时，由MCR-ALS解析的纯物质浓度演化用于构建一种灵敏的HSA光谱生物传感器，其线性范围为1.8 nM至28.1 nM，检测限为0.8 nM。
