Structure, function, and stability of enzymes covalently attached to single-walled carbon nanotubes
Structure, function, and stability of enzymes covalently attached to single-walled carbon nanotubes
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DOI：
10.1021/la702091c
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发表时间：
2007-11-20
期刊：
影响因子：
3.9
通讯作者：
Dordick, Jonathan S.
中科院分区：
文献类型：
--
作者：
Asuri, Prashanth;Bale, Shyam Sundhar;Dordick, Jonathan S.
我们描述了共价连接到单壁碳纳米管 (SWNT) 的酶的结构、活性和稳定性。人们发现，单壁碳纳米管与三种功能上不相关的酶——辣根过氧化物酶、枯草杆菌蛋白酶嘉士伯和鸡蛋清溶菌酶——的结合物可溶于水溶液。此外，分别通过圆二色性和荧光光谱对固定化蛋白质的二级和三级结构进行表征，以及酶动力学的测定表明，酶在附着于单壁碳纳米管后保留了大部分天然结构和活性。相对于其溶液对应物，SWNT-酶缀合物在盐酸胍 (GdnHCl) 和高温下也更稳定。因此，这些蛋白质缀合物代表了新型制剂，同时具有可溶性酶（高活性和低扩散阻力）和固定化酶（高稳定性）的特性，使其成为从诊断、传感到药物输送等应用的有吸引力的选择。
We describe the structure, activity, and stability of enzymes covalently attached to single-walled carbon nanotubes (SWNTs). Conjugates of SWNTs with three functionally unrelated enzymes-horseradish peroxidase, subtilisin Carlsberg, and chicken egg white lysozyme-were found to be soluble in aqueous solutions. Furthermore, characterization of the secondary and tertiary structure of the immobilized proteins by circular dichroism and fluorescence spectroscopies, respectively, and determination of enzyme kinetics revealed that the enzymes retained a high fraction of their native structure and activity upon attachment to SWNTs. The SWNT-enzyme conjugates were also more stable in guanidine hydrochloride (GdnHCl) and at elevated temperatures relative to their solution counterparts. Thus, these protein conjugates represent novel preparations that possess the attributes of both soluble enzymes-high activity and low diffusional resistance-and immobilized enzymes-high stability-making them attractive choices' for applications ranging from diagnostics and sensing to drug delivery.