title: Molecular cloning, expression analysis and enzymatic characterization of cathepsin K from olive flounder (Paralichthys olivaceus).
abstract: We assessed the putative physiological roles of cathepsin K from a flatfish, olive flounder. We cloned a cDNA encoding for cathepsin K (PoCtK), a cysteine protease of the papain family from olive flounder, Paralichthys olivaceus. The tissue-specific expression pattern of PoCtK, determined via real-time PCR analysis, revealed ubiquitous expression in normal tissues with high levels of expression in the spleen and bone marrow. However, PoCtK expression was significantly increased in the muscle and gill at 3-24 h post-injection with bacterial lipopolysaccharide (LPS). The cDNA encoding for the mature enzyme of PoCtK was expressed in Escherichia coli using the pGEX-4T-1 expression vector system. Its activity was quantified via the cleavage of the synthetic peptide Z-Gly-Pro-Arg-MCA, zymography, and the collagen degradation assay. The optimum pH for the protease activity was 8, and the recombinant PoCtK enzyme degraded collagen types I, II, III, IV, and VI and acid-soluble collagen from olive flounder muscle in the presence of chondroitin 4-sulphate (C-4S). Therefore, our data indicate that cathepsin K may play a role in the immune system of fish skin and muscle, in addition to its principal bone-specific function as a collagenolytic enzyme.
authors: Department of Aquatic Life Medicine, Pukyong National University, Busan, Republic of Korea.
authors: Ju Eun
authors: JE
authors: Je
authors: Sang Jung
authors: SJ
authors: Ahn
authors: Na Young
authors: NY
authors: Kim
authors: Jung Soo
authors: JS
authors: Seo
authors: Moo-Sang
authors: MS
authors: Kim
authors: Nam Gyu
authors: NG
authors: Park
authors: Joong Kyun
authors: JK
authors: Kim
authors: Joon Ki
authors: JK
authors: Chung
authors: Hyung Ho
authors: HH
authors: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D056657:Cathepsin K / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004591:Electrophoresis, Polyacrylamide Gel; D005432:Flounder / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins; D056657:Cathepsin K