The Effect of the Binding of ZnO Nanoparticle on the Structure and Stability of α-Lactalbumin: A Comparative Study
The Effect of the Binding of ZnO Nanoparticle on the Structure and Stability of α-Lactalbumin: A Comparative Study
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DOI：
10.1021/jp404411b
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发表时间：
2013-10-31
影响因子：
3.3
通讯作者：
Chakrabarti, Pinak
中科院分区：
文献类型：
--
作者：
Chakraborti, Soumyananda;Sarwar, Shamila;Chakrabarti, Pinak
当纳米粒子暴露在生物流体中时，就会被蛋白质包裹。当蛋白质被吸附在表面时，吸附的程度以及由此对蛋白质构象和活性的影响取决于纳米颗粒的化学性质、形状和大小。我们对a-乳清蛋白(一种形成乳糖合成酶调节亚基的蛋白质)与氧化锌纳米颗粒的相互作用进行了详细的研究。采用溶胶凝胶法制备了纳米粒子，并用透射电子显微镜、X射线衍射仪、紫外可见光谱和光致发光光谱对其进行了表征。结果表明，氧化锌颗粒尺寸为4-7 nm，具有六方结构。用光谱和计算相结合的方法研究了蛋白质与NP的相互作用。用等温量热法对络合作用进行了研究，结果表明，络合作用主要是由熵驱动的，涉及疏水作用。圆二色谱(CD)和傅立叶变换红外光谱(FITR)表明，结合纳米氧化锌后蛋白质的二级结构发生了变化。最后，通过与其他模型蛋白质结合，比较了α-乳清蛋白-NP复合体的结构、功能和稳定性，以更好地了解蛋白质纳米颗粒相互作用的过程。因此，本研究为蛋白质纳米颗粒识别等问题提供了有用的见解。
Nanoparticles (NPs), when exposed to biofluids, become coated with proteins. As the protein is adsorbed on the surface, the extent of adsorption and the consequent effect on protein conformation and activity depend on the chemical nature, shape, and size of the nanoparticle. We have carried out a detailed study on the interaction of a-lactalbumin (a protein which forms the regulatory subunit of lactose synthase) with zinc oxide nanoparticles. The NPs were prepared by the sol gel route and characterized by transmission electron microscopy, X-ray diffraction, UV-visible, and photoluminescence spectroscopy. ZnO particles were found to have a size of 4-7 nm with hexagonal structure. The interaction of protein with NP was examined using a combination of spectroscopic and computational methods. The binding was studied by ITC (isothermal calorimetry), and the result revealed that the complexation is mostly entropy driven and involves hydrophobic interaction. There is alteration in secondary structures in protein on binding ZnO nanoparticle, as revealed by circular dichroism (CD) and Fourier transform infrared spectroscopy (FITR). Finally, a comparison of structure, function, and stability of the alpha-lactalbumin-NP complex has been made by binding ZnO to other model proteins to get a better insight into the process of protein nanoparticle interaction. The present study thus provides useful insights into issues such as protein nanoparticle recognition.