The molecular characterization of a catalase from Chinese mitten crab Eriocheir sinensis. (22nd November 2012)

• Record Type: Journal Article
• Authors: Wang, M.; Wang, L.; Zhou, Z.; Gao, Y.; Wang, L.; Shi, X.; Gai, Y.; Mu, C.; Song, L.
• Is Part Of: International journal of immunogenetics. Volume 40:Number 3(2013:Jun.)
• Page Start: 230
• Page End: 240
• Publication Date: 2012-11-22
• Subjects: Immunogenetics -- Periodicals; 571.9648
• DOI: 10.1111/iji.12019
• Languages: English
• ISSNs: 1744-3121

Abstract

<abstract abstract-type="main" id="iji12019-abs-0001"> <title>Summary</title> <p>Catalase (CAT) is an antioxidant enzyme and plays a significant role in the protection against oxidative stress by reducing hydrogen peroxide. The CAT cDNA of <italic>Eriocheir sinensis</italic> (<italic>Es</italic>CAT) was cloned via RACE technique. The complete sequence of <italic>Es</italic>CAT cDNA consisted of a 5′ untranslated regions (UTR) of 224 bp, a 3′ UTR of 1287 bp with a poly (A) tail and an open reading frame (ORF) of 1542 bp, which encoded a polypeptide of 513 amino acid residues with a calculated molecular mass of approximately 58.86 kDa and a theoretical isoelectric point of 6.880. The deduced amino acid sequence of <italic>Es</italic>CAT contained a highly conserved proximal active‐site signature motif (<sup>60</sup>FDRERIPERVVHAKGAL<sup>76</sup>) and a proximal heme–ligand signature motif (<sup>350</sup>RLFSYNDTH<sup>358</sup>) and exhibited high similarity with other reported CATs. In the phylogenetic tree, <italic>Es</italic>CAT was clustered with the CATs from <italic>Scylla serrata</italic> and <italic>Portunus trituberculatus</italic>. The <italic>Es</italic>CAT transcripts were constitutively expressed in haepatopancreas, haemocytes, gill, gonad, muscle and heart, with highest expression level in haepatopancreas. The relative expression level of <italic>Es</italic>CAT mRNA in haemocytes was continuously up‐regulated and reached the peak level at 48 h post‐<italic>Vibrio anguillarum</italic> challenge. The purified recombinant <italic>Es</italic>CAT protein displayed antioxidant activity against hydrogen peroxide with high thermal stability and broad spectrum of pH values. All these results demonstrated that <italic>Es</italic>CAT was an efficient antioxidant enzyme and potentially involved in the regulation of redox and innate immune response of crabs.</p> </abstract>