Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, IN 47907, USA; Whistler Carbohydrate Research Center, Purdue University, 745 Agricultural Mall Drive, West Lafayette, IN 47907, USA.
Whistler Carbohydrate Research Center, Purdue University, 745 Agricultural Mall Drive, West Lafayette, IN 47907, USA; Department of Food Science, Philip E. Nelson Hall of Food Science, Purdue University, 745 Agricultural Mall Drive, West Lafayette, IN 47907, USA.
Int J Biol Macromol. 2020 Dec 1;164:2753-2760. doi: 10.1016/j.ijbiomac.2020.07.299. Epub 2020 Aug 8.
Amide I and Amide III vibrational modes are frequently used to study protein secondary structure with Fourier transform infrared (FT-IR) spectroscopy. However, for protein mixtures, neither the sole Amide I nor Amide III region provides sufficient information for structural quantitation because of overlapping peaks, especially in the Amide I region. Here, an improved quantitative approach is proposed to estimate secondary structure of protein systems using resolution enhancement and curve-fitting data processing techniques on a gluten model system to investigate structure-function relationships. Twelve different scenarios were prepared to assign bands in the Amide I region. Frequency ranges of 1660-1640 cm and 1665-1660 cm were found to highly contribute to variability in secondary structure contents of samples. Utilization of the Amide III region as a conducive tool to assign bands in the Amide I region led to a better differentiation of some secondary structural motifs and a more accurate quantitation of protein secondary structure. The study presents an understanding of FT-IR data analysis for a quick technique to assess secondary structures of protein mixtures.
酰胺 I 和酰胺 III 振动模式常用于通过傅里叶变换红外（FT-IR）光谱研究蛋白质二级结构。然而，对于蛋白质混合物，由于重叠峰的存在，仅酰胺 I 或酰胺 III 区域都不能提供足够的结构定量信息，尤其是在酰胺 I 区域。在这里，提出了一种改进的定量方法，通过在谷朊模型系统上使用分辨率增强和曲线拟合数据处理技术来估计蛋白质系统的二级结构，以研究结构-功能关系。为了分配酰胺 I 区域的带，准备了 12 种不同的方案。发现 1660-1640 cm 和 1665-1660 cm 的频率范围对样品中二级结构含量的变化有很大贡献。将酰胺 III 区域用作分配酰胺 I 区域带的有利工具，可以更好地区分一些二级结构基序，并更准确地定量蛋白质二级结构。该研究为评估蛋白质混合物的二级结构提供了一种快速技术的 FT-IR 数据分析理解。
