Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 106, Taiwan.
Genomics Research Center, Academia Sinica , Taipei 115, Taiwan.
Langmuir. 2017 Jul 5;33(26):6521-6527. doi: 10.1021/acs.langmuir.7b00578. Epub 2017 Jun 21.
Nanodiamond (ND) is a carbon-based nanomaterial with potential for a wide range of biological applications. One of such applications is to facilitate the nucleation of protein crystals in aqueous solution. Here, we show that NDs (nominal diameters of 30 and 100 nm) after surface oxidation in air and subsequent treatment in strong acids are useful as heterogeneous nucleating agents for protein crystallization. Tested with lysozyme, ribonuclease A, proteinase K, and catalase, the nanomaterials in either aggregate or film form are found to be able to increase the crystallization efficiency of all proteins. Particularly, for 30 nm NDs, the films with an area of ∼2 mm can effectively induce the crystallization of lysozyme at a concentration as low as 5 mg/mL. The efficiency can be further improved by adding preformed protein clusters (∼300 nm in diameter) as inherent nucleation precursors, as demonstrated for ribonuclease A. This combined approach is easy to implement, highly compatible with existing technologies, and can be applied to other protein samples as well.
纳米金刚石（ND）是一种碳基纳米材料，具有广泛的生物应用潜力。其中一种应用是促进蛋白质晶体在水溶液中的成核。在这里，我们表明，在空气中进行表面氧化并随后在强酸中处理后的 ND（名义直径为 30 和 100nm）可用作蛋白质结晶的非均相成核剂。用溶菌酶、核糖核酸酶 A、蛋白酶 K 和过氧化氢酶进行测试，发现纳米材料无论是聚集态还是薄膜态，都能够提高所有蛋白质的结晶效率。特别是对于 30nmND，面积约为 2mm 的薄膜可以在低至 5mg/mL 的浓度下有效地诱导溶菌酶结晶。通过添加预先形成的蛋白质簇（直径约 300nm）作为固有成核前体，可以进一步提高效率，如核糖核酸酶 A 所示。这种组合方法易于实施，与现有技术高度兼容，也可应用于其他蛋白质样品。
