Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States.
Langmuir. 2011 Jun 7;27(11):7042-51. doi: 10.1021/la200388y. Epub 2011 May 9.
Sum frequency generation (SFG) vibrational spectroscopy has been applied to the investigation of peptide immobilization on a polymer surface as a function of time and peptide conformation. Surface immobilization of biological molecules is important in many applications such as biosensors, antimicrobial materials, biobased fuel cells, nanofabrication, and multifunctional materials. Using C-terminus-cysteine-modified cecropin P1 (CP1c) as a model, we investigated the time-dependent immobilization behavior in situ in real time. In addition, potassium phosphate buffer (PB) and mixtures of PB and trifluoroethanol were utilized to examine the effect of peptide secondary structure on CP1c immobilization to polystyrene maleimide (PS-MA). The orientation of immobilized CP1c on PS-MA was determined using polarized SFG spectra. It was found that the peptide solution concentration, solvent composition, and assembly state (monomer vs dimer) prior to immobilization all influence the orientation of CP1c on a PS-MA surface. The detailed relationship between the interfacial peptide orientation and these immobilization conditions is discussed.
和频发生（SFG）振动光谱已被应用于研究肽在聚合物表面的固定，以研究其与时间和肽构象的关系。生物分子的表面固定在许多应用中非常重要，如生物传感器、抗菌材料、生物燃料电池、纳米制造和多功能材料。本文以 C 端半胱氨酸修饰的抗菌肽 CP1（CP1c）为模型，实时原位研究了时间依赖性固定行为。此外，还利用磷酸钾缓冲液（PB）和 PB 与三氟乙醇的混合物研究了肽二级结构对 CP1c 固定到聚苯乙烯马来酰亚胺（PS-MA）的影响。使用偏振和频发生（SFG）光谱确定了固定在 PS-MA 上的 CP1c 的取向。结果发现，肽溶液浓度、溶剂组成以及固定前的组装状态（单体与二聚体）都会影响 CP1c 在 PS-MA 表面的取向。讨论了界面肽取向与这些固定条件之间的详细关系。
