Protein:colloid conjugates for surface enhanced Raman scattering:: Stability and control of protein orientation
Protein:colloid conjugates for surface enhanced Raman scattering:: Stability and control of protein orientation
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DOI：
10.1021/jp982723z
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发表时间：
1998-11-19
影响因子：
3.3
通讯作者：
Natan, MJ
中科院分区：
文献类型：
--
作者：
Keating, CD;Kovaleski, KM;Natan, MJ
制备了细胞色素c（Cc）与胶体Au颗粒的结合物。通过离心/再悬浮纯化的这些缀合物提供了将生物分子分析物定位在两个金属表面之间的可再现的手段：生物分子结合到其上的金属纳米颗粒和用作表面增强拉曼散射（Sers）的基底的聚集的Ag溶胶。通过添加Cc：Au缀合物到聚集的Ag制成的Ag：Cc：Au三明治的Sers光谱显示蛋白质保留其天然构象。在暴露于Sers基底之前，Cc与胶体金属纳米颗粒的缀合可以用作控制蛋白质相对于基底的取向的手段。此外，在吸附到聚集的Ag之前结合到12 nm直径的Au纳米颗粒的Cc分子对于血红素相对于表面的取向的变化和表面诱导的血红素自旋状态转换比吸附的游离Cc更稳定。这些实验表明，蛋白质：Au缀合物作为蛋白Sers的试剂提供了益处。
Conjugates between cytochrome c (Cc) and colloidal Au particles have been prepared. These conjugates, purified by centrifugation/resuspension, provide a reproducible means of positioning a biomolecule analyte between two metal surfaces: the metal nanoparticle to which the biomolecule is bound and an aggregated Ag sol used as a substrate for surface enhanced Raman scattering (SERS). SERS spectra for Ag:Cc:Au sandwiches made by addition of Cc:Au conjugates to aggregated Ag show that the protein retains its native conformation. Conjugation of Cc to colloidal metal nanoparticles prior to exposure to the SERS substrate can be used as a means of controlling protein orientation with respect to the substrate. In addition, Cc molecules bound to 12-nm diameter Au nanoparticles prior to adsorption to aggregated Ag are more stable to changes in the orientation of the heme with respect to the surface and to surface-induced heme spin state conversion than adsorbed, free Cc. These experiments show that protein:Au conjugates offer benefits as reagents for protein SERS.