title: Purification and characterization of hatching enzyme from brine shrimp Artemia salina.
abstract: By using Artemia chorion as a specific substrate, the hatching enzyme from Artemia salina (AHE) was purified by gel-filtration and ion-exchange chromatography, and characterized biochemically and enzymatically in this study. It was found that the AHE had a molecular weight of 82.2 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and often contained 73.3 kDa molecules in preparation. The AHE had obvious choriolytic activity, which was optimal at pH 7.0 and a temperature of 408C. The Km value of the AHE for dimethyl casein was 8.20 mg/ml. The AHE activity was almost completely inhibited by soybean trypsin inhibitor and p-amidinophenyl methane sulfonyl fluoride hydrochloride, greatly inhibited by N-tosyl-L-lysyl chloromethyl ketone, phenylmethanesulfonyl fluoride, and lima bean trypsin inhibitor, slightly inhibited by pepstatin, N-tosyl-L-phenylalanyl chloromethyl ketone, leupeptin, N-ethylmaleimide, and iodoacetamide, and not inhibited by chymostatin and bestatin. All these results imply that AHE is most probably a trypsin-type serine protease. Besides of these, AHE was also sensitive to EDTA and Zn21. Combined with the results that the EDTA-pre-treated HE activity could be perfectly recovered by Zn21, it is indicated that AHE might be also a kind of Zn-metalloprotease.
authors.affiliation: Department of Marine Biology, Ocean University of China, Qingdao, China. tjfan@ouc.edu.cn
authors.forename: Tingjun
authors.initials: T
authors.lastname: Fan
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Wenpeng
authors.initials: W
authors.lastname: Yuan
authors.forename: Qiwang
authors.initials: Q
authors.lastname: Zhong
authors.forename: Ying
authors.initials: Y
authors.lastname: Shi
authors.forename: Rishan
authors.initials: R
authors.lastname: Cong
mesh_terms: D000818:Animals; D001156:Artemia / Q000201:enzymology*; D004789:Enzyme Activation; D004795:Enzyme Stability; D008666:Metalloendopeptidases / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010447:Peptide Hydrolases; D008666:Metalloendopeptidases; C024344:envelysin