Role of the Functionalization of the Gold Nanoparticle Surface on the Formation of Bioconjugates with Human Serum Albumin

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• 作者：Fernando Ca帽averas ; Rafael Madue帽o ; Jos茅 M. Sevilla ; Manuel Bl谩zquez ; Teresa Pineda
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：May 10, 2012
• 年：2012
• 卷：116
• 期：18
• 页码：10430-10437
• 全文大小：358K
• 年卷期：v.116,no.18(May 10, 2012)
• ISSN：1932-7455

文摘

The protein鈥揼old nanoparticle bioconjugates are playing an important role in the studies of biological systems. The nature of the interaction and the magnitude of the binding affinity together with the conformational changes in the protein upon binding are the most addressed topics in relation to the uses of the bioconjugates in different organisms. In this work, we study the human serum albumin (HSA) protein鈥揼old nanoparticle (AuNP) interactions focusing on the nature of the gold nanoparticle surface modification. We have found that the interactions of the HSA with the AuNPs are mainly electrostatic and that the concentration of protein necessary to stabilize the conjugates decreases when the overall negative charge on the nanoparticle surface increases. The changes in the localized surface plasmon resonance (LSPR) signals of the gold nanoparticles (13 nm diameter) are used to determine the number of protein molecules necessary to stabilize the conjugates in a high ionic strength medium. Fluorescence spectroscopy (stationary and time-resolved) is used to characterize the different bioconjugates and determine the binding constants under different experimental conditions. Moreover, the use of an extrinsic fluorescence probe (1-anilino-8-naphthalenesulfonic acid, ANS) gives us some information about the existence of partial unfolding of the protein upon binding to the nanoparticle.