Abstract Reduction of oxygen catalyzed by laccase was studied by surface-enhanced infrared absorption spectroscopy (SEIRAS) combined with electrochemical techniques. Laccase molecules were adsorbed on modified carbon nanotubes (CNTs). SEIRAS provided spectra of Amide I band of adsorbed laccase. Fourier self-deconvolution (FSD) and two-dimensional correlation spectroscopy (2D COS) techniques were employed to reveal the sub-band structure of the Amide I band. The analysis demonstrated that laccase adsorbed on CNTs remains its native state both in the oxidized and reduced states. The detailed analysis showed that change of the oxidation state leads to a small change of the secondary structure of the protein. This change is comparable to the change observed for similar blue-copper oxidases in solution during redox titration. The results of this study demonstrated that CNT's immobilized laccase is an excellent catalyst of oxygen reduction. This study illustrates power of quantitative analysis of IR data to provide information about three-dimensional structure of surface immobilized proteins.

中文翻译：

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吸附在改性碳纳米管上的漆酶催化氧还原过程中结构变化的光谱电化学研究

摘要 采用表面增强红外吸收光谱（SEIRAS）结合电化学技术研究了漆酶催化氧的还原。漆酶分子被吸附在改性碳纳米管 (CNT) 上。SEIRAS 提供了吸附漆酶的酰胺 I 带的光谱。傅里叶自解卷积 (FSD) 和二维相关光谱 (2D COS) 技术被用来揭示 Amide I 带的子带结构。分析表明，吸附在碳纳米管上的漆酶在氧化和还原状态下均保持其天然状态。详细分析表明，氧化态的变化导致蛋白质二级结构的微小变化。这种变化与氧化还原滴定过程中在溶液中观察到的类似蓝铜氧化酶的变化相当。这项研究的结果表明，CNT 的固定化漆酶是一种极好的氧还原催化剂。该研究说明了对红外数据进行定量分析以提供有关表面固定蛋白的三维结构信息的能力。