Isolation and sequence of a novel human chondrocyte protein related to mammalian members of the chitinase protein family.
We describe the isolation of a novel protein from the conditioned medium of human articular cartilage chondrocytes in primary culture. This 39-kDa protein has the N-terminal sequence YKL, which we have termed YKL-39. The 1434-nucleotide sequence of the YKL-39 cDNA predicts a 385-residue initial translation product and a 364-residue mature YKL-39. The amino acid sequence of YKL-39 is most closely related to YKL-40, followed by macrophage chitotriosidase, oviductal glycoprotein, and macrophage YM-1. All five proteins share significant sequence identity with bacterial chitinases and have the probable structure of an (alphabeta)8 barrel. YKL-39 lacks the active site glutamate, which is essential for the activity of chitinases, and as expected has no chitinase activity. The highest level of YKL-39 mRNA expression is seen in chondrocytes, followed by synoviocytes, lung, and heart. YKL-39 accounts for 4% of the protein in chondrocyte-conditioned medium, prostromelysin accounts for 17%, and YKL-40 accounts for 33%. In contrast to YKL-40, YKL-39 is not a glycoprotein and does not bind to heparin.
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Department of Biology, University of California, San Diego, La Jolla, California 92093, USA.
Trinh
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Figueira
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Price
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D054392:Adipokines; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D000071451:Chitinase-3-Like Protein 1; D002688:Chitinases / Q000235:genetics*; D018076:DNA, Complementary; D006023:Glycoproteins / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D037102:Lectins; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D018076:DNA, Complementary; D006023:Glycoproteins; D037102:Lectins; D012333:RNA, Messenger; D002688:Chitinases