Primary structure of a protein isolated from reef shark (Carcharhinus springeri) cartilage that is similar to the mammalian C-type lectin homolog, tetranectin.
During the course of characterization of low molecular weight proteins in cartilage, we have isolated a protein from reef shark (Carcharhinus springeri) cartilage that bears a striking resemblance to the tetranectin monomer originally described by Clemmensen et al. (1986, Eur. J. Biochem. 156, 327-333). The protein was isolated by extraction of neural arch cartilage with 4 M guanidine hydrochloride, dialysis of the extract to bring the guanidine to 0.4 M (reassociating proteoglycan aggregates), followed by cesium chloride density gradient removal of the proteoglycans. The amino acid sequence had 166 amino acids and a calculated molecular weight of 18,430. The shark protein was 45% identical to human tetranectin, indicating that it was in the family of mammalian C-type lectins and that it was likely to be a shark analog of human tetranectin. The function of tetranectin is unknown; it was originally isolated by virtue of its affinity for the kringle-4 domain of plasminogen. Sequence comparison of human tetranectin and the shark-derived protein gives clues to potentially important regions of the molecule.
Neame
P J
PJ
Department of Biochemistry and Molecular Biology, College of Medicine, University of South Florida, Tampa 33620.
Young
C N
CN
Treep
J T
JT
D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D002356:Cartilage / Q000737:chemistry*; D037102:Lectins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D037181:Lectins, C-Type; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D012754:Sharks
D001798:Blood Proteins; D037102:Lectins; D037181:Lectins, C-Type; D010446:Peptide Fragments; C048648:tetranectin