Biomaterial Database

Macular corneal dystrophy: failure to synthesize a mature keratan sulfate proteoglycan. 1980

J R Hassell, and D A Newsome, and J H Krachmer, and M M Rodrigues

Corneal specimens obtained during surgery from patients with macular corneal dystrophy and obtained at autopsy from control eyes were incubated in a medium containing radioactive precursors of glycoproteins and proteoglycans. Biosynthetically radiolabeled material was extracted and characterized by using molecular sieve chromatography and specific enzymes. Cells in control corneas synthesized both a chondroitin sulfate proteoglycan and a keratan sulfate proteoglycan similar to those present in monkey and bovine corneas. Cells in macular corneas synthesized a normal chondroitin sulfate proteoglycan but did not synthesize either keratan sulfate or a mature keratan sulfate proteoglycan. Instead, macular corneas synthesized a glycoprotein with unusually large oligosaccharide side chains. This glycoprotein was not detected in normal corneas and is slightly smaller than normal keratan sulfate proteoglycan. The failure to synthesize a mature keratan sulfate proteoglycan may produce corneal opacity and result in blindness. Because of evidence indicating that the corneal keratan sulfate proteoglycan is normally synthesized through a glycoprotein intermediate [Hart, G. W. & Lennarz, W. (1978) J. Biol. Chem. 253-5795-5801], macular corneal dystrophy may be a defect in glycoprotein processing.

UI	MeSH Term	Description	Entries
D007632	Keratan Sulfate	A sulfated mucopolysaccharide initially isolated from bovine cornea. At least two types are known. Type I, found mostly in the cornea, contains D-galactose and D-glucosamine-6-O-sulfate as the repeating unit; type II, found in skeletal tissues, contains D-galactose and D-galactosamine-6-O-sulfate as the repeating unit.	Keratosulfate,Sulfate, Keratan
D009924	Organ Culture Techniques	A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)	Organ Culture,Culture Technique, Organ,Culture Techniques, Organ,Organ Culture Technique,Organ Cultures
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D011508	Chondroitin Sulfate Proteoglycans	Proteoglycans consisting of proteins linked to one or more CHONDROITIN SULFATE-containing oligosaccharide chains.	Proteochondroitin Sulfates,Chondroitin Sulfate Proteoglycan,Proteochondroitin Sulfate,Proteoglycan, Chondroitin Sulfate,Proteoglycans, Chondroitin Sulfate,Sulfate Proteoglycan, Chondroitin,Sulfate Proteoglycans, Chondroitin
D011509	Proteoglycans	Glycoproteins which have a very high polysaccharide content.	Proteoglycan,Proteoglycan Type H
D002847	Chromatography, Agarose	A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.	Chromatography, Sepharose,Agarose Chromatography,Sepharose Chromatography,Agarose Chromatographies,Chromatographies, Agarose,Chromatographies, Sepharose,Sepharose Chromatographies
D003315	Cornea	The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)	Corneas
D003317	Corneal Dystrophies, Hereditary	Bilateral hereditary disorders of the cornea, usually autosomal dominant, which may be present at birth but more frequently develop during adolescence and progress slowly throughout life. Central macular dystrophy is transmitted as an autosomal recessive defect.	Corneal Dystrophies,Granular Dystrophy, Corneal,Groenouw's Dystrophies,Macular Dystrophy, Corneal,Stromal Dystrophies, Corneal,Corneal Dystrophy,Corneal Dystrophy, Hereditary,Corneal Granular Dystrophies,Corneal Granular Dystrophy,Corneal Macular Dystrophies,Corneal Macular Dystrophy,Corneal Stromal Dystrophies,Corneal Stromal Dystrophy,Dystrophy, Corneal,Dystrophy, Corneal Granular,Dystrophy, Corneal Macular,Dystrophy, Corneal Stromal,Dystrophy, Hereditary Corneal,Groenouw Dystrophies,Groenouws Dystrophies,Hereditary Corneal Dystrophies,Hereditary Corneal Dystrophy,Stromal Dystrophy, Corneal
D006023	Glycoproteins	Conjugated protein-carbohydrate compounds including MUCINS; mucoid, and AMYLOID glycoproteins.	C-Glycosylated Proteins,Glycosylated Protein,Glycosylated Proteins,N-Glycosylated Proteins,O-Glycosylated Proteins,Glycoprotein,Neoglycoproteins,Protein, Glycosylated,Proteins, C-Glycosylated,Proteins, Glycosylated,Proteins, N-Glycosylated,Proteins, O-Glycosylated
D006025	Glycosaminoglycans	Heteropolysaccharides which contain an N-acetylated hexosamine in a characteristic repeating disaccharide unit. The repeating structure of each disaccharide involves alternate 1,4- and 1,3-linkages consisting of either N-acetylglucosamine (see ACETYLGLUCOSAMINE) or N-acetylgalactosamine (see ACETYLGALACTOSAMINE).	Glycosaminoglycan,Mucopolysaccharides