Purification and characterizations of a novel extracellular protease from Shewanella putrefaciens isolated from bigeye tuna  

作　　者：Zhengkai Yi Jun Yan Zhaoyang Ding Jing Xie 

机构地区：[1]College of Food Science&Technology,Shanghai Ocean University,Shanghai,China [2]Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation,Shanghai Ocean University,Shanghai,China [3]National Experimental Teaching Demonstration Center for Food Science and Engineering,Shanghai Ocean University,Shanghai,China [4]Shanghai Engineering Research Center of Aquatic Product Processing&Preservation,Shanghai Ocean University,Shanghai,China

出　　处：《Food Bioscience》2023年第2期334-344,共11页食品生物科学（英文）

基　　金：This research was financially supported by National Natural Science Foundation of China(grant number:31972142,31571914);the earmarked fund for CARS-47;the Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation(20DZ2292200,19DZ1207503).

摘　　要：Shewanella putrefaciens is one of the common spoilage microorganisms in aquatic products,and its extracellular protease is the main cause of seafood spoilage.The characteristics of the extracellular protease produced by S.putrefaciens YZ08 and its hydrolytic properties on fish proteins were studied.After purification,an extracellular protease of 18.78 kDa was obtained and identified as a metalloprotease of the M23 family.The gene encoding this enzyme was cloned and purified by expression in E.coli to obtain a recombinant protease.YZ08 protease showed optimum enzymatic activity at 40℃ and pH 9.0 and was stable at pH 7.0-10.0 and low temperature(<40℃).The kinetic parameters and thermal inactivation parameters of the enzyme were determined.S.putrefaciens YZ08 protease can degrade fish myofibrillar and sarcoplasmic proteins,breaking them down into small particles and low molecular peptides.The three-dimensional structure of the protease was simulated by homology modeling and revealed a correlation between the active site in the protein and substrate specificity.This work provides a foundation for characterizing the properties of S.putrefaciens YZ08 protease and for controlling the quality and safety of seafood.

关 键 词：Shewanella putrefaciens METALLOPROTEINASE CHARACTERIZATION Homology modeling 

分 类 号：TS254[轻工技术与工程—水产品加工及贮藏工程]