Context-Dependent Adsorption Behavior of Cyclic and Linear Peptides on Metal Oxide Surfaces
Context-Dependent Adsorption Behavior of Cyclic and Linear Peptides on Metal Oxide Surfaces
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DOI：
10.1021/la8030304
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发表时间：
2009-02-03
期刊：
影响因子：
3.9
通讯作者：
Choe, Woo-Seok
中科院分区：
文献类型：
--
作者：
Chen, Haibin;Su, Xiaodi;Choe, Woo-Seok
对无机材料具有特异性结合亲和力的肽将生物系统与合成无机材料连接起来。许多无机结合肽是通过组合肽库分离得到的，但对它们的相互作用机制并不了解，这阻碍了这些肽的实际应用。除了氨基酸组成外，肽的结构（例如，被二硫键限制的环状结构）被认为在它们的结合行为中起重要作用。环肽STB 1（-CHKKPSKSC-）先前被鉴定为与TiO 2和SiO 2静电结合。在本研究中，研究了STB 1及其线性形式LSTB 1（-AHKKPSKSA-）在TiO 2或SiO 2表面上的结合行为（亲和力和构象），游离肽、展示肽的噬菌体颗粒和LacI-肽融合蛋白）。定量分析了融合蛋白中STB 1和LSTB 1与任一金属氧化物的结合动力学。LSTB 1在TiO 2和SiO2表面上表现出相似的结合行为。在噬菌体展示和LacI托管肽的背景下，发现STB 1对任一金属氧化物的结合亲和力弱于LSTB 1，但它能够区分SiO2和TiO 2。这可能是因为LSTB 1具有比STB 1更灵活的结构，如分子动力学模拟所示。LSTB 1的结构灵活性使其能够探索更广泛的构象，以最大限度地提高其与TiO 2和SiO 2的相互作用。
Peptides with specific binding affinity to inorganic materials bridge biological systems with synthetic inorganic materials. Many inorganic-binding peptides were isolated using combinatorial peptide libraries without a good understanding of the interaction mechanism, which thus hinders the practical application of these peptides. Besides the amino acid composition, peptides' structure (e.g., cyclic structure constrained by disulfide bond) is believed to play an important role in their binding behavior. A cyclic peptide STB1 (-CHKKPSKSC-) was previously identified to electrostatically bind to TiO2 and SiO2, In the present study, the binding behavior (affinity and conformation) of STB1 and its linear version LSTB1 (-AHKKPSKSA-) on a TiO2 or SiO2 surface was investigated in three different contexts (i.e., free peptides, phage particles displaying peptides, and LacI-peptide fusion protein) using quartz crystal microbalance with energy dissipation measurement (QCM-D). The binding kinetics of STB1 and LSTB1 in the context of fusion protein to either metal oxide was quantitatively analyzed. LSTB1 showed similar binding behavior on both TiO2 and SiO2 surfaces. In the context of phage-displayed and LacI-hosted peptides, STB1 was found to have weaker binding affinity than LSTB1 for either metal oxide, but it was able to distinguish between SiO2 and TiO2. This is probably because LSTB1 has a much more flexible structure than STB1, as shown by the molecular dynamics simulation. The structural flexibility of LSTB1 enables it to explore a wider range of conformations to maximize its interaction with TiO2 and SiO2.