Extraction and structural analysis of isolated proteins from laver Porphyra haitanensis
TAO Fengting, PAN Chuang*, QI Bo, HU Xiao, ZHAO Yongqiang, YANG Xianqing*, YANG Lili
1.College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; 2. Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, National Research and Development Center for Aquatic Product Processing, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; 3.Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China; 4.Guangdong Baiwei Bio Material Company Limited， Huazhou 525100, China
Abstract: To understand effect of ammonium sulfate on the structural property and antioxidant activity of the isolated proteins during separation, the proteins were precipitated by using ammonium sulfate with gradient saturation from laver Porphyrahaitanensis. The physicochemical, structural and spectral properties and differences in their antioxidant activities of target proteins were analzed. The results showed that there was the maximal extraction rate of up to 55.28% by ultrasonic-assisted phosphate buffer treatment. The crude extract of laver P.haitanensis (CEPh) then was precipitated by ammonium sulfate with different saturations and the protein was mainly precipitated at 40% to 60% saturation. UV absorption showed that phycobiliproteins were precipitated at ammonium sulfate saturation varying from 30% to 50%. When the saturation exceeded 50%, however, two non-protein absorption peaks were appeared at 773 and 1 155 cm-1 in the infrared spectra. The Circular Dichroism spectra revealed that the α-helix structure was the main protein structure of the laver, the protein structure of 40%-PhPI being the most orderly. SDS-PAGE indicated that low saturation (10% to 30%) of ammonium sulfate led to significantly improve the precipitation of proteins with relative molecular mass of 55 000, 20 000 and 18 000. The antioxidant tests revealed that the isolated proteins obtained with ammonium sulfate at different saturation had certain antioxidant activities, but with great differences. The finding provides ideas for the extraction method of the laver protein and the selection of saturation range of ammonium sulfate precipitation method, which provides support for the antioxidant activity of the laver protein.
陶凤庭, 潘创, 戚勃, 胡晓, 赵永强, 杨贤庆, 杨莉莉. 坛紫菜分离蛋白的提取与结构解析[J]. 大连海洋大学学报, 2022, 37(5): 850-857.
TAO Fengting, PAN Chuang, QI Bo, HU Xiao, ZHAO Yongqiang, YANG Xianqing, YANG Lili. Extraction and structural analysis of isolated proteins from laver Porphyra haitanensis. Journal of Dalian Ocean University, 2022, 37(5): 850-857.
2022, Vol. 37 
