鲢鱼肉肌原纤维乳糖蛋白的制备及其溶解性

Preparation of neoglycoprotein from silver carp myofibrillar protein with lactose and its solubility

研究了乳糖与鲢鱼肉肌原纤维蛋白(Mf)在不同反应条件下通过美拉德反应制备的肌原纤维乳糖蛋白的功能特性,测定了其在0.1mol/LNaCl溶液中的溶解性,并对其进行了SDS聚丙烯酰胺凝胶电泳分析。乳糖与Mf以1∶1、2∶1、4∶1和6∶1的质量比混合,冷冻干燥后,在50和55℃,相对湿度为65%的条件下反应0～48h制备的肌原纤维乳糖蛋白,其溶解性较Mf有不同程度的提高。乳糖与Mf质量比为1∶1,50℃反应48h后,肌原纤维乳糖蛋白在0.1mol/LNaCl溶液中的溶解性从反应前的18%提高到63%;55℃反应24h,其溶解性达到89%。结果表明,乳糖与鲢鱼肉Mf发生美拉德反应后生成的肌原纤维乳糖蛋白在低离子强度溶液中的溶解性得到了有效提高,乳糖能有选择性地与肌球蛋白重链相结合。

Neoglycoprotein was prepared from silver carp myofibrillar protein by using the Maillard reaction with lactose, and its solubility in a low ionic strength medium was investigated. The lyophilized protein mixed lactose (the weight ratios of lactose and myofibrillar are 1∶1, 2∶1, 4∶1 and 6∶1 respectively) was incubated at 50℃ (0-48h) and 55℃ (0-48h) respectively under 65% RH. Their conjugation dot was researched by SDS-PAGE analysis. After the lyophilized myofibrillar mixed with lactose (the weight ratio 1∶1) was incubated in 50℃ (48h), 55℃ (24h) respectively, and its solubility of glycoprotein increasedfrom 18% to 63% (50℃) and to 89% (55℃) respectively. These results indicated that the solubility of myofibrillar proteins in low ionic strength medium was improved by the Maillard reaction, and the myosin heavy chain was selectively conjugated with lactose.