Cytochrome c Superstructure Biocomposite Nucleated by Gold Nanoparticle: Thermal Stability and Voltammetric Behavior

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• 作者：Xiue Jiang ; Li Shang ; Yuling Wang ; and Shaojun Dong
• 刊名：Biomacromolecules
• 出版年：2005
• 出版时间：November 2005
• 年：2005
• 卷：6
• 期：6
• 页码：3030 - 3036
• 全文大小：188K
• 年卷期：v.6,no.6(November 2005)
• ISSN：1526-4602

文摘

The thermal stability of cytochrome c (cyt c) after Au-nanoparticle-directed association has been studied byvarious spectroscopic (electronic absorption, resonance Raman, and circular dichroism) and electrochemicalmethods. The results show that the thermal stability of the Au-cyt c superstructure biocomposite formedby the electrostatic and hydrophobic interactions among the associated proteins increases significantly. It ismainly caused by strong hydrophobicity of the associated cyt c in Au-cyt c superstructure at high temperature,which results from the compact secondary structure and the packing of hydrophobic side chains around theTrp 59 and heme. In addition, the formation of bis-His configuration of heme is facilitated by the tightlyself-associated state of cyt c in the Au-cyt c superstructure. The electrostatic coupling of the oppositecharges among shells of the adsorbed proteins due to the formation of the superstructure biocomposite canreduce repulsions among the same charges in protein. These factors are also important for enhancing thestability of the associated cyt c. Furthermore, the voltammetric behavior of Au-cyt c at DNA modifiedglassy carbon electrode has been investigated for extending the application of Au-cyt c.