草鱼鳞和草鱼皮胶原蛋白性质及自聚集行为对比研究

Comparative study on characteristics and self-assembly behavior of collagens extracted from skins and scales of grass carp

以草鱼为原料,采取酸-酶结合法提取鱼鳞及鱼皮中胶原蛋白,经紫外光谱(ultraviolet spectrum,UV)、聚丙烯酰胺凝胶电泳(sodium dodecyl sulphate-polyacrylamide gel electrophoresis,SDS-PAGE)、傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)以及差示扫描量热法(differential scanning calorimetry,DSC)对比其结构性质,采用浊度实验、聚集程度实验和扫描电镜(scanning electronic microscopy,SEM)比较2种胶原蛋白的体外自聚集行为。结果表明,提取的2种胶原蛋白均具有2条α链,为典型I型胶原蛋白,并保持了良好的三螺旋结构,鱼鳞、鱼皮的变性温度分别为34.99℃和39.75℃。在30℃的中性盐溶液条件下,2种胶原蛋白均可产生自聚集行为且鱼皮、鱼鳞胶原蛋白的聚集程度分别为28%和27.33%。经SEM观察到2种来源胶原蛋白均能自聚集形成交织状纤维,其中鱼鳞胶原蛋白的网状纤维结构更加明显并具有胶原原纤维的周期性横纹D带,而鱼皮胶原蛋白自聚集的胶原纤维结构有一定坍塌且无D带。

Collagens were extracted from the grass carp skin and scale by acid-enzyme combination method.Their structural properties were analyzed by ultraviolet spectrum(UV),sodium dodecyl sulphate-polyacrylamide gel electrophoresis(SDS-PAGE),fourier transform infrared spectroscopy(FTIR) and differential scanning calorimetry(DSC). Self-assembly behavior of collagens were compared by turbidity experiment,fibril formation detection and scanning electronic microscopy(SEM). The results indicated that collagens from grass carp skin and scale were characterized as type I collagen with two α-chains and a triple helix structure. Denaturation temperatures of the collagens were 34. 99 ℃ and 39. 75 ℃,respectively. The self-assembly curves showed that the collagens could self-assemble into fibrils at 30 ℃ near neutral pH with Na Cl,and self-assembly degree of collagens were similar from skin 28% and scale 27. 33%. Scanning electronic microscopy observations suggested that both collagens could form intertwine fibril network. The reticular fibrous structure of scale collagen was more obvious than skin collagen,and a periodic striped D-band was observed,while the skin collagen fiber structure had a collapse without D-band.