Molecular Characterization and Tissue Expression of Carboxypeptidase H (CPH) Gene in Flounder (Paralichthys olivaceus)

Carboxypeptidase H (CPH) is one of several enzymes required for the processing of peptide hormone precursors and removal of basic amino acids from intermediates during protein biosynthesis. The CPH gene was isolated from a flounder (Paralichthys olivaceus) brain cDNA library and was found to consist of 1,590 bp encoding 455 amino acids residues. The nucleotide sequence of the CPH gene was compared with those of other species, including zebrafish and mouse, and turned out to be conserved during evolution. Expression of CPH mRNA was confirmed by both Reverse transcription polymerase Chain Reaction (RT-PCR) and Northern blot analysis. A recombinant protein of approximately 50 kDa, which corresponds to CPH, was functionally expressed in E. coli. Biochemical studies on the expressed protein were performed. We report here the molecular characteristics and tissue expression of newly identified CPH cDNA from flounder (P. olivaceus).