氧化还原血红素蛋白介导的CdSe/ZnS量子点荧光

Redox heme-proteins mediated fluorescence of CdSe/ZnS quantum dots.

作者信息

Qin Lixia, He Luwei, Ji Congcong, Li Xiangqing, Kang Shi-Zhao, Mu Jin

机构信息

School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418, China.

出版信息

J Photochem Photobiol B. 2014 Apr 5;133:65-72. doi: 10.1016/j.jphotobiol.2014.02.017. Epub 2014 Mar 19.

DOI:10.1016/j.jphotobiol.2014.02.017

PMID:24705372

Abstract

The redox properties of cytochrome c (Cyt c), hemoglobin (Hb) and myoglobin (Mb) were studied based on electrostatic interactions between Thioglycolic acid (TGA) capped CdSe/ZnS quantum dots (QDs) and proteins. Results indicated that only Cyt c quenched the fluorescence of the QDs at pH>8.0. Under the optimized conditions, a significant fluorescence recovery of the QDs' system was observed when the reduced form of Cyt c incubated with TGA capped QDs, however, the reduced state of Hb and Mb resulted in a more fluorescence quenching on the same size of QDs. Interestingly, the fluorescence changes of QDs-proteins could be switched by modulating the redox potentials of proteins-attached QDs. Moreover, only the oxidized Cyt c form was reduced by the generated O2(-) that significantly enhanced the fluorescence of the QDs' system, which was also demonstrated by fluorescence imaging in HeLa cells.

摘要

基于巯基乙酸（TGA）包覆的CdSe/ZnS量子点（QDs）与蛋白质之间的静电相互作用，研究了细胞色素c（Cyt c）、血红蛋白（Hb）和肌红蛋白（Mb）的氧化还原特性。结果表明，仅在pH>8.0时Cyt c会猝灭量子点的荧光。在优化条件下，当还原型Cyt c与TGA包覆的量子点孵育时，观察到量子点体系有显著的荧光恢复，然而，还原态的Hb和Mb在相同尺寸的量子点上导致更多的荧光猝灭。有趣的是，量子点-蛋白质的荧光变化可通过调节附着有蛋白质的量子点的氧化还原电位来切换。此外，只有氧化型Cyt c形式被生成的O2(-)还原，这显著增强了量子点体系的荧光，这也通过HeLa细胞中的荧光成像得到了证明。