Dufour E, Robert P, Bertrand D, Haertlé T
LEIMA, Institut National de la Recherche Agronomique, Nantes, France.
J Protein Chem. 1994 Feb;13(2):143-9. doi: 10.1007/BF01891973.
Fourier transform infrared spectroscopy has been applied to investigate the secondary structural changes of beta-lactoglobulin in water/ethanol mixtures. The studies were carried out at two different pHs and at high protein concentrations. The spectra were recorded using an attenuated total reflection cell. The amide I band of beta-lactoglobulin in water reveals large amounts of intra extended beta-sheet structure. About 20% ethanol, beta-lactoglobulin unfolds and beta-strand formation is observed. alpha-Helices are built up by increasing the ethanol concentration up to 30%. In 50% ethanol, beta-lactoglobulin gels providing the apparent pH are neutral. The secondary structural changes of beta-lactoglobulin were observed on the similarity maps obtained by Principal Component Analysis.
傅里叶变换红外光谱法已被用于研究β-乳球蛋白在水/乙醇混合物中的二级结构变化。这些研究在两种不同的pH值和高蛋白浓度下进行。使用衰减全反射池记录光谱。β-乳球蛋白在水中的酰胺I带显示出大量的内部延伸β-折叠结构。在约20%乙醇中，β-乳球蛋白展开并观察到β-链的形成。通过将乙醇浓度提高到30%，α-螺旋得以形成。在50%乙醇中，β-乳球蛋白形成凝胶，前提是表观pH值为中性。通过主成分分析获得的相似性图谱上观察到了β-乳球蛋白的二级结构变化。
