CCDC Army Research Laboratory, Weapons and Material Research Directorate, 6300 Rodman Road, Aberdeen, Proving Ground, Maryland 21005, United States.
DoD Blast Injury Research Coordinating Office, U.S. Army Medical Research and Development Command, 504 Scott Street, Fort Detrick, Maryland 21702, United States.
J Phys Chem Lett. 2020 Dec 3;11(23):10278-10282. doi: 10.1021/acs.jpclett.0c03054. Epub 2020 Nov 20.
Confinement has profound effects on protein functions. Nanoscale probes for confinement or excluded volume interactions could help us understand how these interactions influence protein functions. This work reports on the increased luminescence of BSA-gold nanoclusters when confined. Confinement of the BSA-gold nanoclusters occurred within reverse micelles (RMs), where the size of the RMs determined the degree of confinement. The confinement-enhanced luminescence is reversible, i.e., the emission returns to its original value following cyclic changes in RM size. Circular dichroism measurements show an increase in alpha-helical character of the BSA-stabilized nanoclusters with confinement, which could provide a mechanism for the increase in luminescence. The alpha-helical character of the native proteins also increases with confinement, suggesting that the protein-nanocluster might sense confinement in an analogous fashion as the proteins. When the RMs approach the size of the protein, the intensity becomes independent of alpha-helical character, suggesting a different mechanism for the luminescence increase.
confinement 对蛋白质功能有深远的影响。用于 confinement 或 excluded volume 相互作用的纳米级探针可以帮助我们了解这些相互作用如何影响蛋白质功能。本工作报告了 BSA-金纳米团簇在受限情况下的发光增强。BSA-金纳米团簇的 confinement 发生在反胶束（RMs）内，其中 RMs 的大小决定了 confinement 的程度。受限增强的发光是可逆的，即随着 RM 大小的循环变化，发射会恢复到原始值。圆二色性测量显示，BSA 稳定的纳米团簇的 alpha-螺旋特征随 confinement 增加，这可能为发光增加提供了一种机制。天然蛋白质的 alpha-螺旋特征也随 confinement 增加，这表明蛋白质-纳米团簇可能以类似的方式感知 confinement。当 RMs 接近蛋白质的大小时，强度变得与 alpha-螺旋特征无关，这表明发光增强的机制不同。
