Conformational Change Induced Reversible Assembly/Disassembly of Poly-L-lysine-Functionalized Gold Nanoparticles
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- 作者：Yi Guo ; Yudan Ma ; Li Xu ; Jun Li ; Wensheng Yang
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：July 5, 2007
- 年：2007
- 卷：111
- 期：26
- 页码：9172 - 9176
- 全文大小：216K
- 年卷期：v.111,no.26(July 5, 2007)
- ISSN：1932-7455
文摘
The poly-L-lysine-functionalized gold nanoparticle (PLL-GNP) was found to undergo reversible assembly/disassembly in the range of pH from 6.5 to 11.0 at room temperature. At a high pH value, the deprotonatedlysine residues allow the formation of 
-helix and 
-sheet structures at the expense of a part of random coiland -turn structures, thus inducing the assembly of GNPs. With a decrease of pH to 6.5, the assembly ofGNPs is disrupted due to the conversion of the -helix and -sheet back into the random and -turn. It isidentified that the formation/collapse of an antiparallel -sheet structure among PLL chains from adjacentGNPs is responsible for reversible pH-dependent assembly/disassembly of GNPs. Since the conformation-induced assembly/disassembly process of the PLL-GNP can be well recognized by a shift of the surfaceplasmon resonance band of the GNP and the color change of the solution, this study presents the possibilityof following the conformation change of a peptide by monitoring the spectral change of the GNP.
-helix and -sheet structures at the expense of a part of random coiland -turn structures, thus inducing the assembly of GNPs. With a decrease of pH to 6.5, the assembly ofGNPs is disrupted due to the conversion of the -helix and -sheet back into the random and -turn. It isidentified that the formation/collapse of an antiparallel -sheet structure among PLL chains from adjacentGNPs is responsible for reversible pH-dependent assembly/disassembly of GNPs. Since the conformation-induced assembly/disassembly process of the PLL-GNP can be well recognized by a shift of the surfaceplasmon resonance band of the GNP and the color change of the solution, this study presents the possibilityof following the conformation change of a peptide by monitoring the spectral change of the GNP.