Morphology and structural properties of pH-responsive amphiphilic peptides.
Morphology and structural properties of pH-responsive amphiphilic peptides.
复制标题
pH 响应型两亲肽的形态和结构特性。
DOI：
10.1166/jnn.2010.2996
复制
发表时间：
2010
影响因子：
--
通讯作者：
Sun,XiuzhiSusan
中科院分区：
文献类型：
--
作者：
Shera,JeanneN;Takahashi,Daisuke;Herrera,AlvaroI;Prakash,Om;Sun,XiuzhiSusan
肽水平的蛋白质纳米材料在医学应用方面显示出巨大的潜力。当肽暴露于溶剂成分或 pH 值的变化时，由于自组装特性的变化，肽会改变其形态构象。设计了两个 15 残基肽序列 KhK (KKKFLIVIGSIIKKK) 和交替 Kh (KFLKKIVKIGKKSII)，用于确定肽序列对溶液形态和构象的作用。当溶剂条件在酸性 pH 值下从水变为三氟乙醇/水溶液时，KhK 溶液表现出无规卷曲到螺旋的转变。然而，通过圆二色光谱和 2D-1H–1H 核磁共振光谱测定，交替的 Kh 溶液在相似的溶剂和 pH 条件下主要表现出无规卷曲特征。在碱性pH下，圆二色光谱和核磁共振光谱分析表明，KhK的无规卷曲特征在碱性pH下增加，而交替Kh表现出片特征的增加。透射电子显微镜的进一步分析显示肽溶液形态存在显着差异。两种肽序列的溶剂组成和 pH 值显着影响肽颗粒聚集和纤维形成。
Protein nanomaterials at the peptide level have shown great potential for medical applications. Peptides change their morphological conformation because of changes in self-assembly properties when they are exposed to changes in solvent composition or pH. Two 15-residue peptide sequences, KhK (KKKFLIVIGSIIKKK) and Alternating Kh (KFLKKIVKIGKKSII), were designed for the purpose of determining the role of peptide sequence on solution morphology and conformation. KhK solutions exhibited a random coil to helical transition when solvent conditions were changed from water to a trifluorethanol/water solution at acidic pH. Alternating Kh solutions, however, demonstrated primarily random coil character under similar solvent and pH conditions as determined by circular dichroism spectroscopy and 2D-1H–1H nuclear magnetic resonance spectroscopy. At basic pH, circular dichroism spectroscopy and nuclear magnetic resonance spectroscopy analysis demonstrated that random coil character increased at basic pH for KhK, whereas Alternating Kh exhibited an increase in -sheet character. Further analysis by transmission electron microscopy showed marked differences in the peptide solution morphology. Peptide particle aggregation and fiber formation were significantly affected by solvent composition and pH values for both peptide sequences.