caa a22 4500 606229736 CHVBK 20210128101210.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10695-015-0099-9 doi (NATIONALLICENCE)springer-10.1007/s10695-015-0099-9 Identification, mRNA expression profiling and activity characterization of cathepsin L from red drum ( Sciaenops ocellatus ) [Elektronische Daten] [Bo-guang Sun, Yong-hua Hu] Cathepsin L is a cysteine protease with a papain-like structure. It is known to be implicated in multiple processes of mammalian immune response to pathogen infection. In teleost fish, the functionality of cathepsin L is less understood. In this work, we characterized a cathepsin L homologue (designated as SoCatL) from red drum Sciaenops ocellatus, an important farmed fish species in China. SoCatL possesses a typical domain arrangement characteristic of cathepsin L, which comprises a proregion and a protease domain with four catalytically essential residues (Gln137, Cys143, His282 and Asn302) conserved in various organisms. SoCatL shares moderate sequence identities with mammalian cathepsin L and relatively high sequence identities with teleost cathepsin L. Phylogenetic analysis revealed that SoCatL is evolutionally close to fish cathepsin L, especially those belonging to the Perciformes order. The homology model of SoCatL was discovered to exhibit a structure resembling human cathepsin L. Transcriptional expression of SoCatL was found ubiquitous in tissues and enhanced after experimental infection with a bacterial pathogen. Recombinant SoCatL purified from Escherichia coli (designated as rSoCatL) displayed apparent proteolytic activity, which was optimal at 50°C and pH 7.0. The activity of rSoCatL required the catalytic residue Cys143 and was severely reduced by cathepsin inhibitor. These results suggest that SoCatL is a teleost cathepsin L homologue which functions as a cysteine protease and is likely to participate in the host immune response against bacterial infection. Springer Science+Business Media Dordrecht, 2015 Cathepsin L nationallicence Sciaenops ocellatus nationallicence Teleost fish nationallicence Red drum nationallicence Sun Bo-guang Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China aut Hu Yong-hua Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China aut Fish Physiology and Biochemistry Springer Netherlands 41/6(2015-12-01), 1463-1473 0920-1742 41:6<1463 2015 41 10695 https://doi.org/10.1007/s10695-015-0099-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10695-015-0099-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sun Bo-guang Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China aut NATIONALLICENCE 700 1- Hu Yong-hua Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, 266071, Qingdao, China aut NATIONALLICENCE 773 0- Fish Physiology and Biochemistry Springer Netherlands 41/6(2015-12-01), 1463-1473 0920-1742 41:6<1463 2015 41 10695