State Key Laboratory of Food Science and Technology, and School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China.
Food Chem. 2013 Nov 15;141(2):662-8. doi: 10.1016/j.foodchem.2013.03.079. Epub 2013 Apr 6.
This study aimed to establish the influence of protein oxidation on the ability of magnesium pyrophosphate (PP) to dissociate actomyosin. Actomyosin isolated from pork muscle then suspended in 0.1M NaCl at pH 6.2 was oxidatively stressed with 10 μM FeCl3/0.1mM ascorbate/1mM H2O2 for 6 or 12h at 4°C. Protein oxidation was evidenced by the loss of myosin and actin, the concomitant formation of disulphide-cross-linked polymers, and elevated myosin ATPase activity. The intrinsic viscosity of oxidized actomyosin had a weaker response to PP-Mg(2+) than that of non-oxidized actomyosin, indicating the suppression of actomyosin dissociation. Moreover, oxidized actomyosin solutions were devoid of small particles (<10nm) and the stressed actomyosin exhibited weaker binding of PP-Mg(2+) than non-oxidized, which further suggested a reduced myosin-PP interaction and subsequent dissociation of the actomyosin complexes.
本研究旨在探讨蛋白质氧化对焦磷酸镁（PP）解离肌动球蛋白能力的影响。从猪肉肌肉中分离出肌动球蛋白，然后悬浮在 pH 值为 6.2 的 0.1M NaCl 中，在 4°C 下用 10 μM FeCl3/0.1mM 抗坏血酸/1mM H2O2 氧化应激 6 或 12 小时。通过肌球蛋白和肌动蛋白的丢失、二硫键交联聚合物的形成以及肌球蛋白 ATP 酶活性的升高，证明了蛋白质的氧化。与非氧化肌动球蛋白相比，氧化肌动球蛋白的固有粘度对 PP-Mg(2+)的响应较弱，表明肌动球蛋白的解离受到抑制。此外，氧化肌动球蛋白溶液中缺乏小于 10nm 的小颗粒，并且应激肌动球蛋白与非氧化肌动球蛋白相比，与 PP-Mg(2+)的结合较弱，这进一步表明肌球蛋白与 PP 的相互作用减少，随后肌动球蛋白复合物解离。
