罗非鱼皮胶原酶抑制肽的制备、体外活性及其理化特性研究

Preparation,in vitro activity and physicochemical properties of colla-genase inhibitory peptide from tilapia

罗非鱼皮富含胶原蛋白,是一种制备生物活性肽的理想原料。以罗非鱼皮为原料,采用酶解法制备罗非鱼皮胶原酶抑制肽(Tilapia skin collagenase inhibitory peptide,TSCIP),并对其胶原酶抑制活性与金属离子结合活性的相关性进行研究,以期为罗非鱼加工副产物的高值化利用与食物蛋白源胶原酶抑制剂的研发提供参考。结果表明,罗非鱼皮经碱性蛋白酶酶解4 h后的产物具有最高的胶原酶抑制活性和锌离子(Zn^(2+))、镁离子(Mg^(2+))结合活性,并探明其主要由小分子肽(<1000 D占85.65%)组成。紫外、傅里叶变换红外光谱以及圆二色谱分析显示,TSCIP与Zn^(2+)、Mg^(2+)以及胶原酶结合后其二级结构发生了变化,β-折叠含量明显增加;Zn^(2+)、Mg^(2+)主要通过羧基氧、氨基氮原子以及羰基与TS-CIP结合,胶原酶主要通过氨基氮原子以及羰基与TSCIP结合。

Tilapia skin,rich in collagen,is an ideal raw material for preparation of bioactive peptides.To provide references for the high-value utilization of tilapia processing by-products and the development of food protein-derived collagenase inhibitors,we prepared tilapia skin collagenase inhibitory peptide(TSCIP)from tilapia skin by enzymatic hydrolysis,and studied the correlation between its collagenase inhibitory activity and metal ion binding activity.The results show that the tilapia skin product hydrolyzed by alkaline protease for 4 h had the highest collagenase inhibition activity,as well as Zn^(2+)and Mg^(2+)binding activity,and it was mainly composed of small molecular peptides(<1000 D accounting for 85.65%).Ultraviolet(UV),Fourier transform infrared(FTIR)and circular dichroism(CD)analysis show that the secondary structure of TSCIP changed after binding with Zn^(2+),Mg^(2+)and collagenase,and the β-sheet content of TSCIP increased significantly.Zn^(2+)and Mg^(2+)bind to TSCIP mainly through carboxyl oxygen,amino nitrogen atoms and carbonyl groups,while collagenase binds to TSCIP mainly through amino nitrogen atoms and carbonyl groups.