Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles.
Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles.
复制标题
DOI：
10.1021/acsnano.7b06600
复制
发表时间：
2017-12-26
期刊：
影响因子：
17.1
通讯作者：
Brust M
中科院分区：
文献类型：
--
作者：
Grzelczak MP;Danks SP;Klipp RC;Belic D;Zaulet A;Kunstmann-Olsen C;Bradley DF;Tsukuda T;Viñas C;Teixidor F;Abramson JJ;Brust M
碳硼烷修饰的金纳米粒子(Au/Carborane NPs，2-3 nm)可以作为人工离子转运体穿过生物膜。颗粒本身是大的疏水阴离子，能够在水介质中分散，并在磷脂双层膜的两侧进行分配。因此，它们的存在引起膜电位，根据能斯特方程，膜电位由膜两侧颗粒的相对浓度确定。这些颗粒倾向于吸附在膜的两侧，如果膜电位的变化需要它们的重新分配，则可以翻转。这种变化可以通过电化学池中的恒电位器进行，也可以通过与另一种分配离子竞争来实现，例如，钾离子在其特定转运体呋喃霉素存在的情况下。碳硼烷包裹的金纳米粒子有一个充满空洞的配位体外壳，这些空洞源于近球形配体在接近球形的金属核心上的堆积。这些空隙通常由钠离子或钾离子填充，金属核心中的多余电子过度补偿了电荷。因此，阴离子粒子能够吸收和释放一定的阳离子负载，并相应地调整它们的净电荷。电势依赖的荧光光谱表明，微囊极化后的磷脂膜可以通过微粒介导的离子传输而去极化。研究还表明，在恒电位控制下，这些颗粒可以作为碱性离子的特定转运体穿过独立的膜。镁离子不会被运输。
Carborane-capped gold nanoparticles (Au/carborane NPs, 2–3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with a potentiostat in an electrochemical cell or by competition with another partitioning ion, for example, potassium in the presence of its specific transporter valinomycin. Carborane-capped gold nanoparticles have a ligand shell full of voids, which stem from the packing of near spherical ligands on a near spherical metal core. These voids are normally filled with sodium or potassium ions, and the charge is overcompensated by excess electrons in the metal core. The anionic particles are therefore able to take up and release a certain payload of cations and to adjust their net charge accordingly. It is demonstrated by potential-dependent fluorescence spectroscopy that polarized phospholipid membranes of vesicles can be depolarized by ion transport mediated by the particles. It is also shown that the particles act as alkali-ion-specific transporters across free-standing membranes under potentiostatic control. Magnesium ions are not transported.
登录
查看更多内容
影响因子：
--
作者：
Bayley H;Cronin B;Heron A;Holden MA;Hwang WL;Syeda R;Thompson J;Wallace M
通讯作者：
Wallace M
影响因子：
56.9
作者：
Doyle, DA;Cabral, JM;MacKinnon, R
通讯作者：
MacKinnon, R
影响因子：
15
作者：
Holden, Matthew A.;Needham, David;Bayley, Hagan
通讯作者：
Bayley, Hagan
影响因子：
38.3
作者：
Burns, Jonathan R.;Seifert, Astrid;Howorka, Stefan
通讯作者：
Howorka, Stefan
影响因子：
4.6
作者：
SMITH, HD;OBENLAND, CO;PAPETTI, S
通讯作者：
PAPETTI, S