海洋经济软体动物肌肉副肌球蛋白分布特性初探

以肌肉组织的蛋白为切入点,探索海洋经济软体类主要可食部位的化学特性与差异,并对软体类副肌球蛋白的分布特点进行初步探索。研究对象为商品活体经济软体类,包括菲律宾蛤仔、毛蚶、脉红螺、皱纹盘鲍及长蛸5个种类。首先,对可食部位化学组成及氨基酸组成进行分析比较,结果显示,5种软体动物间一般化学组成差别不大,肌肉中均含有17种氨基酸,且亮氨酸和赖氨酸含量均较高,氨基酸含量无显著差异。然后,对肌肉组织蛋白组分及各组分含量分布进行分析与比较,SDS-PAGE分析表明,5种软体动物肌肉中均含有肌球蛋白、肌动球蛋白、副肌球蛋白及原肌球蛋白等重要组分;同时在菲律宾蛤仔、毛蚶及皱纹盘鲍的肌肉中含有分子量高于200 ku的未知蛋白聚合物。基于质谱分析鉴定并结合分子量进一步计算,确定该蛋白聚合物为副肌球蛋白聚合体。综上可知,不同软体类肌肉蛋白组分分布的差异主要体现在副肌球蛋白,因此,副肌球蛋白及其聚合体的分布特性值得进一步探索。

Muscular Paramyosin Distribution in Different Commercial Species of Mollusks

The approximate and amino acid compositions were analyzed focusing on paramyosin in edible parts of 5 commercial species in mollusks including manila clam Ruditapes philippinarum , ark shell Scapharca subcrenata , disc abalone Haliotis discus hannai , conch Rapana vanosa , and octopus Octopus variabilis to explore the mechanism of muscle protein and food quality of commercial mollusks. It was found that there were 17 amino acids in all 5 species, higher contents of leucine and lysine than those of other essential amino acids. SDS-PAGE analysis indicated that myosin, paramyosin, actin and tropomyosin were found in protein components, including unknown aggregates with molecular weight of more than 200 ku in Manila clam, ark shell, and abalone. Mass spectrometric analysis revealed that the unknown aggregate was an aggregate of paramyosin which is reflected in distribution of protein components in different mollusks, indicating that the role of paramyosin and/or paramyosin aggregate in muscle protein is worth further study.