华贵栉孔扇贝闭壳肌蛋白的分离提取及性质

Protein Isolation and Characterization of the Adductor Muscle of Chlamys nobilis

以华贵栉孔扇贝为研究对象，对其闭壳肌蛋白组分进行分离，并对其氨基酸组成、分子质量分布和热稳定性进行检测分析。结果表明：新鲜华贵栉孔扇贝闭壳肌中水分、粗蛋白含量分别为78.12%、18.19%；蛋白组分分离得到3种组成蛋白，其中肌原纤维蛋白占总蛋白46.80%，基质蛋白占32.70%，肌浆蛋白占20.50%；氨基酸组成检测表明3种蛋白组分氨基酸种类齐全，肌浆蛋白、肌原纤维蛋白、基质蛋白中必需氨基酸占氨基酸总量的百分比分别达到41.52%、38.96%、35.49%；十二烷基磺酸钠-聚丙烯酰胺凝胶电泳分析显示：肌浆蛋白亚基分子质量在16～105 kD之间分布广泛；肌原纤维蛋白组分分子质量大多介于35～50 kD和105 kD附近；基质蛋白组分在35～50 kD之间有2条明显的条带，在71 kD附近也有一条带；热稳定性分析显示肌浆蛋白、肌原纤维蛋白、基质蛋白的变性温度分别为65.8、50.5、59.6℃。

Adductor muscle is an important edible part of Chlamys nobilis which has been processed and exploited as a rich source of protein due to its delicious taste. In this paper, amino acid analysis, molecular weight distribution and thermal stability were investigated on adductor muscle protein fromChlamys nobilis. The results demonstrated that the contents of moisture and protein in adductor muscle fromChlamys nobilis were 78.12% and 18.19%, respectively. Three protein components were isolated from adductor muscle including myofibrillar protein, myostromin and myosinogen representing 46.80%, 32.70% and 20.5% of the total proteins, respectively. The analysis of amino acid composition indicated that a wide variety of amino acids were found in the three proteins with essential to total amino acid ratios of 41.52%, 38.96% and 35.49% for myosinogen, myofibrillar protein and myostromin, respectively. sodium dodecyl sulfate-polyacrylamide gelelectrophoresis （SDS-PAGE） analysis showed that the subunit molecular weights of myosinogen were in the range of 16～ 105 kD, those of myofibrillar protein mostly ranged from 35 to 50 kD and near 105 kD, and myostromin had two obvious bands between 35 and 50 kD and one band near 71 kD. Thermal stability analysis indicated that the denaturation temperature of myosinogen, myofibrillar protein, mystromin was 65.8, 50.5 and 59.6℃, respectively.