Nascimento Glauber G, Salay Luiz C, Sanches Paulo R S, Cilli Eduardo M
Department of Exact Sciences and Technology, State University of Santa Cruz, UESC, Rodovia Jorge Amado, Km 16, CEP: 45662-900, Ilhéus, BA, Brazil.
Protein Pept Lett. 2016;23(9):790-4. doi: 10.2174/0929866523666160615010315.
Investigating interactions of designed peptide-based biomaterials with lipid membranes is important for applications in nanobiotechnology. Here the interaction of an ornithine-rich pH-responsive peptide called P11-5 with a model membrane was investigated employing Fourier transform infrared spectroscopy (FTIR). The results showed that in the range of pH 6.0-8.0 the peptide P11-5 shows spectral features which are evidence of the presence of peptides with antiparallel beta-sheet conformation (bands in the range 1625-1615 cm-1), as also spectral features which indicate the existence of random coil conformation (bands in the range 1640-1648 cm-1). Two types of membranes were used, 1,2- dipalmitoyl-sn-3-glycero-phosphocholine (DPPC) membranes with zwitterionic head groups and 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (sodium salt) (DPPG) membranes with anionic head groups. It was showed that there was a distinct peptide interaction under different pH values, pH 6.0, 7.0 and 8.0 for each type of lipid membrane with DPPC membrane preventing the peptide self-association even at basic pH, while for DPPG membrane there was a more evident peptide-lipid interaction. FTIR measurements indicate that in the presence of DPPC membrane the peptide was prevented to form beta-sheet aggregates at basic pH, while in the presence of DPPG membranes the self-association behavior of the peptide was more similar to its behavior when in aqueous solution in the absence of lipid membranes. Such results are important for the potential development of novel biomolecular nanostructured materials by the physico-chemical understanding of the peptide-lipid interactions.
研究基于肽的设计生物材料与脂质膜之间的相互作用对于纳米生物技术的应用至关重要。在此，利用傅里叶变换红外光谱（FTIR）研究了一种名为P11-5的富含鸟氨酸的pH响应肽与模型膜之间的相互作用。结果表明，在pH 6.0 - 8.0范围内，肽P11-5呈现出光谱特征，这证明了具有反平行β-折叠构象的肽的存在（1625 - 1615 cm-1范围内的谱带），同时也有表明存在无规卷曲构象的光谱特征（1640 - 1648 cm-1范围内的谱带）。使用了两种类型的膜，具有两性离子头部基团的1,2 - 二棕榈酰 - sn - 3 - 甘油 - 磷酸胆碱（DPPC）膜和具有阴离子头部基团的1,2 - 二棕榈酰 - sn - 甘油 - 3 - [磷酸 - rac -（1 - 甘油）]（钠盐）（DPPG）膜。结果表明，在不同pH值下存在明显的肽相互作用，对于每种类型的脂质膜，在pH 6.0、7.0和8.0时，DPPC膜即使在碱性pH下也能防止肽的自缔合，而对于DPPG膜，肽 - 脂质相互作用更为明显。FTIR测量表明，在DPPC膜存在下，肽在碱性pH下被阻止形成β-折叠聚集体，而在DPPG膜存在下，肽的自缔合行为与其在无脂质膜的水溶液中的行为更为相似。这些结果对于通过对肽 - 脂质相互作用的物理化学理解来潜在开发新型生物分子纳米结构材料具有重要意义。
