Articular Cartilage Superficial Zone Protein (SZP) Is Homologous to Megakaryocyte Stimulating Factor Precursor and Is a Multifunctional Proteoglycan with Potential Growth-Promoting, Cytoprotective, and Lubricating Properties in Cartilage Metabolism

We have performed cDNA sequencing and homology analyses to elucidate the complete amino acid composition for a superficial zone protein (SZP) from human and bovine cartilage which has previously been shown to be a proteoglycan specifically synthesized by chondrocytes located at the surface of bovine articular cartilage and also some synovial lining cells. The results of this study indicate that cartilage SZP is homologous with a glycoprotein...