Interaction of Polyethyleneimine-Functionalized ZnO Nanoparticles with Bovine Serum Albumin

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• 作者：Soumyananda Chakraborti ; Prachi Joshi ; Devlina Chakravarty ; Virendra Shanker ; Z. A. Ansari ; Surinder P. Singh ; Pinak Chakrabarti
• 刊名：Langmuir
• 出版年：2012
• 出版时间：July 31, 2012
• 年：2012
• 卷：28
• 期：30
• 页码：11142-11152
• 全文大小：473K
• 年卷期：v.28,no.30(July 31, 2012)
• ISSN：1520-5827

文摘

In biological fluids, nanoparticles are always surrounded by proteins. As the protein is adsorbed on the surface, the extent of adsorption and the effect on the protein conformation and stability are dependent on the chemical nature, shape, and size of the nanoparticle (NP). We have carried out a detailed investigation on the interaction of bovine serum albumin (BSA) with polyethyleneimine-functionalized ZnO nanoparticles (ZnO-PEI). ZnO-PEI was synthesized using a wet chemical method with a core size of 3鈥? nm (from transmission electron microscopy). The interaction of BSA with ZnO-PEI was examined using a combination of calorimetric, spectroscopic, and computational techniques. The binding was studied by ITC (isothermal titration calorimetry), and the result revealed that the complexation is enthalpy-driven, indicating the possible involvement of electrostatic interaction. To investigate the nature of the interaction and the location of the binding site, a detailed domain-wise surface electrostatic potential calculation was performed using adaptive Poisson鈥揃oltzmann software (APBS). The result shows that the protein surface can bind the nanoparticle. On binding ZnO-PEI, the protein gets destabilized to some extent, as displayed by CD (circular dichroism) and FTIR (Fourier transform infrared) spectroscopy. Chemical and thermal denaturation of BSA, when carried out in the presence of ZnO-PEI, also indicated a small perturbation in the protein structure. A comparison of the enthalpy and entropy components of binding with those derived for the interaction of BSA with ZnO nanoparticles explains the effect of hydrophilic cationic species attached on the NP surface. The effect of the NP surface modification on the structure and stability of BSA would find useful applications in nanobiotechnology.