PROTEIN METAL INTERACTIONS IN PROTEIN-COLLOID CONJUGATES PROBED BY SURFACE-ENHANCED RAMAN-SPECTROSCOPY
PROTEIN METAL INTERACTIONS IN PROTEIN-COLLOID CONJUGATES PROBED BY SURFACE-ENHANCED RAMAN-SPECTROSCOPY
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DOI：
10.1021/la00050a009
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发表时间：
1991-02-01
期刊：
影响因子：
3.9
通讯作者：
GARRELL, RL
中科院分区：
文献类型：
--
作者：
AHERN, AM;GARRELL, RL
表面增强拉曼（SER）光谱已被用于评估胶体免疫探针中的蛋白质-金属相互作用。 胶体金与抗兔IgG、白蛋白-生物素或蛋白A的缀合物中没有可检测的信号，这表明蛋白质没有化学吸附在金属颗粒上。 类似地，白蛋白、白蛋白-生物素和蛋白A不与胶体银共价结合，而是最初吸附在银上，蛋白水合壳完整。 在一段时间内，新的SER带出现在白蛋白光谱中，这是由于芳香族氨基酸的振动。 这意味着在界面附近的蛋白质中发生构象变化。 这些变化的时间尺度与圆二色性和紫外-可见光谱所观察到的一致。 抗生物素蛋白对生物素与胶体金属探针结合的影响也已被表征。 Sers结果表明，生物素结合到一个裂缝或口袋状结构的抗生物素蛋白，限制生物素表面的相互作用。 这项研究表明，SER光谱表征蛋白质-金属相互作用和吸附的生物分子络合的可用性的实用性。
Surface-enhanced Raman (SER) spectroscopy has been used to assess protein-metal interactions in colloidal immunoprobes. The absence of a detectable signal from conjugates of colloidal gold with anti-rabbit IgG, albumin-biotin, or protein A suggests that the proteins are not chemisorbed on the metal particles. Similarly, albumin, albumin-biotin, and protein A are not covalently bound to colloidal silver, but rather adsorb on silver initially with the protein hydration shell intact. Over a period of days, new SER bands appear in the albumin spectrum that are attributed to vibrations of aromatic amino acids. This implies that conformational changes are occurring in the protein near the interface. The time scale for these changes is consistent with what has been observed by circular dichroism and UV-visible spectroscopy. The effect of avidin on the binding of biotin to colloidal metal probes has also been characterized. The SERS results indicate that biotin binds to a cleft or pocketlike structure in avidin, restricting biotin-surface interactions. This study demonstrates the utility of SER spectroscopy for characterizing protein-metal interactions and the availability of adsorbed biomolecules for complexation.