Green Fluorescent Protein in Inertially Injected Aqueous Nanodroplets

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• 作者：Jianyong Tang ; Ana M. Jofre ; Geoffrey M. Lowman ; Rani B. Kishore ; Joseph E. Reiner ; Kristian Helmerson ; Lori S. Goldner ; Mark E. Greene
• 刊名：Langmuir
• 出版年：2008
• 出版时间：May 6, 2008
• 年：2008
• 卷：24
• 期：9
• 页码：4975 - 4978
• 全文大小：142K
• 年卷期：v.24,no.9(May 6, 2008)
• ISSN：1520-5827

文摘

We inertially inject and study the contents of optically trappable aqueous nanodroplets (hydrosomes) emulsifiedin a perfluorinated matrix. A new piezoelectric actuated device for production of single hydrosomes on demand isintroduced. Hydrosomes containing enhanced green fluorescent protein (EGFP) were injected, optically trapped, andheld at the focus of an excitation laser in a confocal microscope, and single-molecule photobleaching events wereobserved. The rotational diffusion time of EGFP in trapped hydrosomes was measured using time-resolved fluorescenceanisotropy. In free solution, the mean rotational diffusion time was determined to be 13.8 ± 0.1 ns at 3 s/entities/mgr.gif">M and 14.0± 0.2 ns at 10 s/entities/mgr.gif">M. In hydrosomes, the mean rotational diffusion time was similar and determined to be 12.6 ± 1.0ns at 3 s/entities/mgr.gif">M and 15.5 ± 1.6 ns at 10 s/entities/mgr.gif">M. We conclude that the rotational motion inside the nanodroplets is consistentwith rotation in free solution and that the protein therefore does not aggregate at the water-oil interface. Protein canbe confined in hydrosomes with high efficiency using this technique, which provides an alternative to surface attachmentor lipid encapsulation and opens up new avenues of research using single molecules contained in fluid nanovolumes.