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 …