School of Food and Biological Engineering, Jiangsu University, Zhenjiang, Jiangsu Province 212013, China.
Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Food Res Int. 2023 Jan;163:112204. doi: 10.1016/j.foodres.2022.112204. Epub 2022 Nov 20.
In order to study the effect of oxidation on the dye-binding behavior of myofibrillar proteins, selected dyes with different charges (positively charged Sarfarin O (SO), neutral bromophenol blue (BPB), and negatively charged Orange G (OG)) were incubated with myofibrils oxidized by the Fenton system with HO (10 mM). Upon oxidation, loss of free thiols, formation of carbonyls, particle size, and hydrophobicity of myofibrillar proteins (MPs) increased. The absolute value of Zeta-potential increased by 14.48 % after oxidation, the myofibrillar proteins shifted to a more acidic isoelectric point (pI) upon oxidation. Oxidation decreased net positive charges of myofibrillar protein and the binding ability of MPs towards OG in the environment with pH less than pI and the affinity of MPs towards SO in the environment with pH more than pI were thus increased. Here we propose a hypothesis that oxidation-induced change in net charges is the driving force affecting the amount of protein-bound dye. This paper aims to examine the effect of oxidation on the net charges of myofibrillar proteins and to provide insight into the mechanism of oxidation-induced changes in protein-bound dyes.
为了研究氧化对肌原纤维蛋白染料结合行为的影响，选择了带有不同电荷的染料（带正电荷的 Sarfarin O（SO）、中性溴酚蓝（BPB）和带负电荷的 Orange G（OG））与 Fenton 体系中由 HO（10 mM）氧化的肌原纤维孵育。氧化后，肌原纤维蛋白（MPs）的游离巯基损失、羰基形成、粒径和疏水性增加。氧化后 Zeta 电位的绝对值增加了 14.48%，氧化后肌原纤维蛋白转移到更酸性的等电点（pI）。氧化降低了肌原纤维蛋白的净正电荷，并且 MPs 在 pH 小于 pI 的环境中对 OG 的结合能力降低，而在 pH 大于 pI 的环境中 MPs 对 SO 的亲和力增加。本文提出了一个假设，即氧化诱导的净电荷变化是影响蛋白质结合染料量的驱动力。本文旨在研究氧化对肌原纤维蛋白净电荷的影响，并深入了解氧化诱导的蛋白质结合染料变化的机制。
