Abstract：
BACKGROUND: This study explored the denaturation of 11S globulin, a protein known for its diverse functional properties in soy protein applications, at pH 3.0 and pH 10.0, followed by a gradual return to pH 7.0 to facilitate renaturation. It investigated the structural and functional changes during renaturation induced by a change in pH, revealing the stabilization mechanism of 11S globulin.
RESULTS: The findings revealed that during pH adjustment to neutral, the denatured soybean 11S globulin - resulting from alkaline (pH 10.0) or acidic (pH 3.0) treatments - experienced a refolding of its extended tertiary structure to varying extents. The particle size and the proportions of α-helix and β-sheet in the secondary structure aligned progressively with those of the natural-state protein. However, for the alkali-denatured 11S, the β-sheet content decreased upon adjustment to neutral, whereas an increase was observed for the acid-denatured 11S. In terms of functional properties, after alkaline denaturation, the foaming capacity (FC) and emulsifying activity index (EAI) of 11S increased by 1.4 and 1.2 times, respectively, in comparison with its native state. The solubility, foamability, and emulsifiability of the alkali-denatured 11S gradually diminished during renaturation but remained superior to those of the native state. Conversely, these properties showed an initial decline, followed by an increase during renaturation triggered by pH neutralization.
CONCLUSIONS: This research contributes to the enhancement of protein functionality, offering a theoretical foundation for the development of functional soy protein products and expanding their potential applications. © 2024 Society of Chemical Industry.
RESULTS: The findings revealed that during pH adjustment to neutral, the denatured soybean 11S globulin - resulting from alkaline (pH 10.0) or acidic (pH 3.0) treatments - experienced a refolding of its extended tertiary structure to varying extents. The particle size and the proportions of α-helix and β-sheet in the secondary structure aligned progressively with those of the natural-state protein. However, for the alkali-denatured 11S, the β-sheet content decreased upon adjustment to neutral, whereas an increase was observed for the acid-denatured 11S. In terms of functional properties, after alkaline denaturation, the foaming capacity (FC) and emulsifying activity index (EAI) of 11S increased by 1.4 and 1.2 times, respectively, in comparison with its native state. The solubility, foamability, and emulsifiability of the alkali-denatured 11S gradually diminished during renaturation but remained superior to those of the native state. Conversely, these properties showed an initial decline, followed by an increase during renaturation triggered by pH neutralization.
CONCLUSIONS: This research contributes to the enhancement of protein functionality, offering a theoretical foundation for the development of functional soy protein products and expanding their potential applications. © 2024 Society of Chemical Industry.
摘要：
背景：这项研究探索了11S球蛋白的变性，一种以其在大豆蛋白应用中的多种功能而闻名的蛋白质，在pH3.0和pH10.0下，随后逐渐恢复至pH7.0以促进复性。它研究了pH诱导的复性过程中的结构和功能变化，揭示了11S球蛋白的稳定机理。
结果：研究结果表明，在将pH值调节至中性时，变性的大豆11S球蛋白-由碱性（pH10.0）或酸性（pH3.0）处理产生-经历了其扩展的三级结构的不同程度的重折叠。二级结构中α-螺旋和β-折叠的颗粒大小和比例逐渐与天然状态蛋白质一致。然而,对于碱变性的11S，β-折叠含量在调整为中性后下降，而酸变性的11S则增加。在功能特性方面,碱变性后，11S的发泡能力（FC）和乳化活性指数（EAI）分别提高了1.4和1.2倍，分别,与它的原生状态相比。溶解度,起泡性，碱变性11S的乳化性在复性过程中逐渐减弱，但仍优于天然状态。相反，这些属性显示出最初的下降，随后是由pH中和引发的复性过程中的增加。
结论：这项研究有助于增强蛋白质的功能，为开发功能性大豆蛋白产品和拓展其潜在应用提供了理论基础。本文受版权保护。保留所有权利。
结果：研究结果表明，在将pH值调节至中性时，变性的大豆11S球蛋白-由碱性（pH10.0）或酸性（pH3.0）处理产生-经历了其扩展的三级结构的不同程度的重折叠。二级结构中α-螺旋和β-折叠的颗粒大小和比例逐渐与天然状态蛋白质一致。然而,对于碱变性的11S，β-折叠含量在调整为中性后下降，而酸变性的11S则增加。在功能特性方面,碱变性后，11S的发泡能力（FC）和乳化活性指数（EAI）分别提高了1.4和1.2倍，分别,与它的原生状态相比。溶解度,起泡性，碱变性11S的乳化性在复性过程中逐渐减弱，但仍优于天然状态。相反，这些属性显示出最初的下降，随后是由pH中和引发的复性过程中的增加。
结论：这项研究有助于增强蛋白质的功能，为开发功能性大豆蛋白产品和拓展其潜在应用提供了理论基础。本文受版权保护。保留所有权利。
