Proteoglycans/chemistry; Animals; Blotting, Northern; CHO Cells; Cell Line; Chondroitin Sulfates/chemistry; Cricetinae; DNA, Complementary/metabolism; Decorin; Escherichia coli/metabolism; Extracellular Matrix Proteins; Glycosaminoglycans/chemistry; Glycosides/chemistry; Glycosylation; HeLa Cells; Humans; Hydrogen-Ion Concentration; Kinetics; Models, Genetic; Mutagenesis, Site-Directed; Mutation; Oligosaccharides/chemistry; Protein Isoforms; Protein Structure, Tertiary; Proteoglycans/genetics; Proteoglycans/metabolism; Recombinant Proteins/chemistry; Temperature; Time Factors; Tunicamycin/pharmacology; Uridine Diphosphate Xylose/chemistry; Vaccinia virus/metabolism; Xylose/chemistry