Blondelle S E, Ostresh J M, Houghten R A, Pérez-Payá E
Torrey Pines Institute for Molecular Studies, San Diego, California 92121.
Biophys J. 1995 Jan;68(1):351-9. doi: 10.1016/S0006-3495(95)80194-3.
Specific conformational effects have been reported for amphipathic model peptides upon binding of defined hydrophobic domains to nonpolar stationary phases during reversed-phase high performance liquid chromatography (RP-HPLC). Such induced conformations are found to be especially pronounced for peptides that are amphipathic in an alpha-helical conformation. Such induced amphipathic conformations resulted in substantially later elution than predicted using amino acid-based retention coefficients. In the present study, the induced conformational behavior of model peptides observed during RP-HPLC was correlated with their secondary structure as determined by circular dichroism (CD) spectroscopy in both aqueous solution and C18-mimetic environments. The experimental retention times of the peptides studied were found to correlate with their CD spectra in the presence of lipids, whereas a poor correlation was observed with their CD spectra in the presence of trifluoroethanol. A new approach was developed to evaluate the induction of secondary structure in peptides due to interactions at aqueous/lipid interfaces, which involves the measurement of the CD ellipticities of peptides bound to a set of C18-coated quartz plates. An excellent correlation was found in this environment between the RP-HPLC retention times and CD ellipticities of the bound peptides.
在反相高效液相色谱（RP-HPLC）过程中，当两亲性模型肽的特定疏水结构域与非极性固定相结合时，已报道了特定的构象效应。发现这种诱导构象对于呈α-螺旋构象的两亲性肽尤为明显。这种诱导的两亲性构象导致洗脱时间比使用基于氨基酸的保留系数预测的要晚得多。在本研究中，RP-HPLC过程中观察到的模型肽的诱导构象行为与其在水溶液和C18模拟环境中通过圆二色性（CD）光谱测定的二级结构相关。研究发现，所研究肽的实验保留时间与其在脂质存在下的CD光谱相关，而在三氟乙醇存在下观察到与它们的CD光谱相关性较差。开发了一种新方法来评估由于在水/脂质界面的相互作用而导致的肽二级结构的诱导，该方法涉及测量与一组C18涂层石英板结合的肽的CD椭圆率。在这种环境下，发现结合肽的RP-HPLC保留时间与CD椭圆率之间具有极好的相关性。
