Thermophilic Ferritin 24mer Assembly and Nanoparticle Encapsulation Modulated by Interdimer Electrostatic Repulsion.
Thermophilic Ferritin 24mer Assembly and Nanoparticle Encapsulation Modulated by Interdimer Electrostatic Repulsion.
复制标题
DOI：
10.1021/acs.biochem.7b00296
复制
发表时间：
2017-07-18
期刊：
影响因子：
2.9
通讯作者：
Dmochowski IJ
中科院分区：
文献类型：
--
作者：
Pulsipher KW;Villegas JA;Roose BW;Hicks TL;Yoon J;Saven JG;Dmochowski IJ
蛋白质笼自组装使小分子、大分子和纳米材料的封装和隔离成为可能，用于生物纳米技术中的许多应用。值得注意的是，野生型嗜热铁蛋白（AfFtn）存在于低离子强度的四螺旋束蛋白的稳定二聚体，和蛋白质形成一个中空的组装体的24个原聚体在高离子强度（10800 mM NaCl）。这种组装过程也可以由溶液中的高电荷金纳米颗粒（AuNP）引发，从而导致封装。这些数据表明，盐溶液或带电的金纳米粒子可以屏蔽不利的静电相互作用在AfFtn二聚体-二聚体界面，但具体的“热点”残基控制组装尚未确定。为了进一步研究这一点，我们通过计算设计了三种AfFtn突变体（E65 R、D138 K、A127 R），其在沿沿着二聚体-二聚体界面的位点处引入单个正电荷。这些蛋白质表现出不同的组装动力学和热力学，其按照增加的24聚体倾向的顺序排列：A127 R < WT <D138 K> E65 R。E65 R在宽范围的离子强度（0 - 800 mM NaCl）下组装到24聚体，并且24聚体的解离温度为98 °C。X射线晶体结构分析的E65 R突变体确定了一个更紧凑，闭孔笼的几何形状。A127 R和D138 K突变体表现出野生型封装和稳定5-nm AuNP的能力，而E65 R获得了保持以apo形式组装的能力。这项工作说明了设计的蛋白质笼具有独特的组装和封装特性。
Protein cage self-assembly enables encapsulation and sequestration of small molecules, macromolecules, and nanomaterials for many applications in bionanotechnology. Notably, wild-type thermophilic ferritin from Archaeoglobus fulgidus (AfFtn) exists as a stable dimer of four-helix bundle proteins at low ionic strength, and the protein forms a hollow assembly of 24 protomers at high ionic strength (∼800 mM NaCl). This assembly process can also be initiated by highly charged gold nanoparticles (AuNPs) in solution, leading to encapsulation. These data suggest that salt solutions or charged AuNPs can shield unfavorable electrostatic interactions at AfFtn dimer-dimer interfaces, but specific “hot-spot” residues controlling assembly have not been identified. To investigate this further, we computationally designed three AfFtn mutants (E65R, D138K, A127R) that introduce a single positive charge at sites along the dimer-dimer interface. These proteins exhibited different assembly kinetics and thermodynamics, which were ranked in order of increasing 24mer propensity: A127R < WT < D138K ≪ E65R. E65R assembled to the 24mer across a wide range of ionic strengths (0 – 800 mM NaCl), and the dissociation temperature for the 24mer was 98 °C. X-ray crystal structure analysis of the E65R mutant identified a more compact, closed-pore cage geometry. A127R and D138K mutants exhibited wild-type ability to encapsulate and stabilize 5-nm AuNPs, whereas E65R gained ability to remain assembled in apo-form. This work illustrates designed protein cages with distinct assembly and encapsulation properties.
登录
查看更多内容
DOI：
10.1107/s090744491003982x
发表时间：
2011-04
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Evans PR
通讯作者：
Evans PR
影响因子：
5.6
作者：
Calhoun, JR;Kono, H;Saven, JG
通讯作者：
Saven, JG
影响因子：
15
作者：
Abe, Satoshi;Hirata, Kunio;Watanabe, Yoshihito
通讯作者：
Watanabe, Yoshihito
影响因子：
2.9
作者：
Khare, Garima;Nangpal, Prachi;Tyagi, Anil K.
通讯作者：
Tyagi, Anil K.
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH