Zhou Aimei, Lin Liying, Liang Yan, Benjakul Soottawat, Shi Xiaoling, Liu Xin
Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
Food Chem. 2014 Aug 1;156:402-7. doi: 10.1016/j.foodchem.2014.02.013. Epub 2014 Feb 12.
Changes of physicochemical properties in natural actomyosin (NAM) from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure (200, 400, 600MPa for 10, 30, 50min) were studied. The increase in turbidity of NAM was coincidental with the decrease in protein solubility with increasing pressure and time, suggesting the formation of protein aggregates. SDS-PAGE showed that polymerisation and degradation of myosin heavy chain were induced by high pressure. Ca(2+)-ATPase activity of NAM treated by high pressure was lost, suggesting the denaturation of myosin and the dissociation of actomyosin complex. Surface hydrophobicity of NAM increased when the pressure and pressurization time increased, indicating that the exposed hydrophobic residues increased upon application of high pressure. Decrease in total sulfhydryl content and increase in surface-reactive sulfhydryl content of NAM samples were observed with the extension of pressurizing time, indicating the formation of disulphide bonds through oxidation of SH groups or disulphide interchanges. The above changes of physicochemical properties suggested conformational changes of NAM from muscle of threadfin bream induced by high hydrostatic pressure.
研究了高静水压（200、400、600MPa，处理10、30、50分钟）对金线鱼（Nemipterus spp.）天然肌动球蛋白（NAM）理化性质的影响。随着压力和时间的增加，NAM的浊度增加，同时蛋白质溶解度降低，这表明形成了蛋白质聚集体。SDS-PAGE显示高压诱导了肌球蛋白重链的聚合和降解。高压处理的NAM的Ca(2+)-ATPase活性丧失，表明肌球蛋白变性和肌动球蛋白复合物解离。随着压力和加压时间的增加，NAM的表面疏水性增加，这表明施加高压后暴露的疏水残基增加。随着加压时间的延长，NAM样品的总巯基含量降低，表面反应性巯基含量增加，这表明通过SH基团的氧化或二硫键交换形成了二硫键。上述理化性质的变化表明高静水压诱导金线鱼肌肉中的NAM发生了构象变化。
