Computational de novo design and characterization of a protein that selectively binds a highly hyperpolarizable abiological chromophore.
Computational de novo design and characterization of a protein that selectively binds a highly hyperpolarizable abiological chromophore.
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DOI：
10.1021/ja4067404
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发表时间：
2013-09-18
影响因子：
15
通讯作者：
Therien MJ
中科院分区：
文献类型：
--
作者：
Fry HC;Lehmann A;Sinks LE;Asselberghs I;Tronin A;Krishnan V;Blasie JK;Clays K;DeGrado WF;Saven JG;Therien MJ
这项工作报告了第一个例子的单链蛋白质计算设计包含四个α-螺旋片段和折叠，形成一个4-螺旋束封装一个超分子生物生色团，具有特殊的非线性光学性质。命名为SCRPZ-1的109个残基的蛋白质以1：1的化学计量在水性缓冲溶液中结合并分散不溶性超极化发色团钌（II）[5-（4′-乙炔基-（2，2 ′;6′，2 ″-三联吡啶基））-10，20-双（苯基）卟啉]锌（II）-（2，2 ′;6′，2 ″-三联吡啶）2+（RuPZn）。一个1：1的结合化学计量的holoprotein的支持电子吸收和CD光谱，以及平衡分析ultracenthegation和尺寸排阻色谱。SCRPZ-1在μM浓度下容易二聚化，并且蛋白质外部的经验性重新设计产生了稳定的单体蛋白质SCRPZ-2，其也显示出1：1的蛋白质：辅因子化学计量。对于水性缓冲液中的两种蛋白质，包封的辅因子显示出与有机溶剂中的稀释RuPZn辅因子所表现出的那些相似的物理化学性质：飞秒、纳秒和微秒时间尺度的泵浦-探测瞬态吸收光谱数据表明具有大光谱带宽的强吸收全蛋白激发态，其穿透近红外（NIR）能量区域;全蛋白电子激发三重态显示出RuPZn发色团的微秒时间尺度寿命特征。在1340 nm的入射照射波长（λinc）下对这些全蛋白进行的超瑞利光散射（HRS）测量表明了异常的动态超极化率（β1340 = 3100 × 10−30 esu）。X射线反射率测量确定，这种从头设计的超极化蛋白质可以以高表面密度共价连接到硅表面，而不会损失辅因子，这表明这些组件提供了一种新的方法来获得具有独特电光功能的生物启发材料。
This work reports the first example of a single-chain protein computationally designed to contain four α-helical segments and fold to form a 4-helix bundle encapsulating a supramolecular abiological chromophore that possesses exceptional nonlinear optical properties. The 109-residue protein designated SCRPZ-1, binds and disperses an insoluble hyperpolarizable chromophore, ruthenium(II) [5-(4′-ethynyl-(2,2′;6′,2″-terpyridinyl))-10,20-bis(phenyl)porphinato]zinc(II)-(2,2′;6′,2″-terpyridine)2+ (RuPZn) in aqueous buffer solution at a 1:1 stoichiometry. A 1:1 binding stoichiometry of the holoprotein is supported by electronic absorption and CD spectra, as well as equilibrium analytical ultracentrifugation and size exclusion chromatography. SCRPZ-1 readily dimerizes at μM concentrations, and an empirical redesign of the protein exterior produced a stable monomeric protein, SCRPZ-2, that also displayed a 1:1 protein:cofactor stoichiometry. For both proteins in aqueous buffer, the encapsulated cofactor displays photophysical properties resembling those exhibited by the dilute RuPZn cofactor in organic solvent: femtosecond-, nanosecond-, and microsecond-timescale pump-probe transient absorption spectroscopic data evince intensely absorbing holoprotein excited states having large spectral bandwidth that penetrate deep in the near-infrared (NIR) energy regime; the holoprotein electronically excited triplet state exhibits a microsecond timescale lifetime characteristic of the RuPZn chromophore. Hyper-Rayleigh light scattering (HRS) measurements carried out at an incident irradiation wavelength (λinc) of 1340 nm for these holoproteins demonstrate an exceptional dynamic hyperpolarizabilty (β1340 = 3100 × 10−30 esu). X-ray reflectivity measurements establish that this de novo designed hyperpolarizable protein can be covalently attached with high surface density to a silicon surface without loss of the cofactor, indicating that these assemblies provide a new approach to bio-inspired materials that have unique electro-optic functionality.
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影响因子：
15
作者：
Karki, L;Vance, FW;Therien, MJ
通讯作者：
Therien, MJ
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