Cloning and Expression of a cDNA Coding for Catalase from Zebrafish (Daniorerio)

A full-length complementary DNA (cDNA) clone encoding a catalase was amplif ied by the rapid amplication of cDNA ends-polymerase chain reaction (RACE-P CR) technique from zebrafish (Danio rerio) mRNA. Nucleotide sequence analys is of this cDNA clone revealed that it comprised a complete open reading fr ame coding for 526 amino acid residues and that it had a molecular mass of 59 654 Da. The deduced amino acid sequences showed high similarity with the sequences of catalase from swine (86.9%), mouse (85.8%), rat (85%), human (83.7%), fruit fly (75.6%), nematode (71.1%), and yeast (58.6%). The amino acid residues for secondary structures are apparently conserved as they are present in other mammal species. Furthermore, the coding region of zebrafi sh catalase was introduced into an expression vector, pET-20b(+), and trans formed into Escherichia coli expression host BL21(DE3)pLysS. A 60-kDa activ e catalase protein was expressed and detected by Coomassie blue staining as well as activity staining on polyacrylamide gel followed electrophoresis.