title: Analysis of the proteoglycans synthesized by corneal explants from embryonic chicken. II. Structural characterization of the keratan sulfate and dermatan sulfate proteoglycans from corneal stroma.
abstract: Radioisotopically labeled proteoglycans were isolated from a 4 M guanidine HCl, 2% Triton X-100 extract of corneal stroma from day 18 chicken embryos by anion-exchange chromatography. Two predominant proteoglycans in the sample were separated by octyl-Sepharose chromatography using a gradient elution of detergent in 4 M guanidine HCl. One proteoglycan had an overall mass of approximately 125 kDa, a single dermatan sulfate chain (approximately 85-90% chondroitin 4-sulfate, low iduronate content) of approximately 65 kDa, and a core protein after chondroitinase ABC digestion of approximately 45 kDa which also contained one to three N-linked oligosaccharides and one O-linked oligosaccharide. The other proteoglycan had an overall size of approximately 100 kDa, two to three keratan sulfate chains of approximately 15 kDa each, and a core protein following keratanase digestion of approximately 51 kDa which included two to three N-linked but no O-linked oligosaccharides. A larger size, a greater overall hydrophobicity (as measured by its interaction with octyl-Sepharose) and an absence of O-linked oligosaccharides argue that this core protein is a distinct gene product from the core protein of the dermatan sulfate proteoglycan.
authors.affiliation: Proteoglycan Chemistry Section, National Institute of Dental Research, Bethesda, Maryland 20892.
authors.forename: R J
authors.initials: RJ
authors.lastname: Midura
authors.forename: V C
authors.initials: VC
authors.lastname: Hascall
mesh_terms: D000818:Animals; D002642:Chick Embryo; D002807:Chondroitin / Q000031:analogs & derivatives*; D002852:Chromatography, Ion Exchange; D003315:Cornea / Q000378:metabolism*; D003871:Dermatan Sulfate / Q000032:analysis* / Q000096:biosynthesis; D006025:Glycosaminoglycans / Q000032:analysis*; D007632:Keratan Sulfate / Q000032:analysis* / Q000096:biosynthesis; D008970:Molecular Weight
chemical_list: D006025:Glycosaminoglycans; D003871:Dermatan Sulfate; D002807:Chondroitin; D007632:Keratan Sulfate