Molecular characterization of a novel cathepsin b from striped murrel channa striatus: Bioinformatics analysis, gene expression, synthesis of peptide and antimicrobial property

Özet

In this study, we have reported a full length cDNA of cathepsin B identified from the constructed cDNA library of snakehead murrel Channa striatus by genome sequence FLX technology. The identified full length C. striatus cathepsin B (Cs Cath B) is 1486 base pairs (bp) long which contains 990 bp open reading frame (ORF). The ORF region encodes 330 amino acids with a mo lecular mass of 36 k Da. This amino acid sequence contains three thiol protease motifs at 101 -112, 275 - 285 and 292 -311 with their respective active sites viz., Cys 107, His 277 and Asp 297 . CsCath B exhibited the maximum similarity (87%) with Cath B from mang rove red snapper, Lutjanus argentimaculatus . Phylogenetically, CsCath B is clustered together with the fish groups belonging to perciformes. A predicted 3D model of Cs Cath B revealed 11 &#945;-helix and 10 &#946; -strands. Cs Cath B contains higher percentage (10%) of coils due to the presence of many glycine residues (36 residues). The highest gene expression (P<0.05) was noticed in liver. Further, the expression was induced with fungal ( Aphanomyces invadans ) and bacterial (Aeromonas hydrophila ) infections. The predic ted antimicrobial region of Cs Cath B was synthesized to study its antimicrobial property. The peptide exhibited the antimicrobial activity towards Gram negative and Gram positive bacteria. The overall results indicate that CsCath B is a potential molecule for further studies on murrel defense mechanism.