Proteoglycan biosynthesis by human corneas from patients with types 1 and 2 macular corneal dystrophy

Journal Article · Sat Sep 15 00:00:00 EDT 1990 · Journal of Biological Chemistry; (USA)

OSTI ID:6367192

Midura, R J; Hascall, V C; MacCallum, D K; Meyer, R F; Thonar, E J; Hassell, J R; Smith, C F; Klintworth, G K ^[1]

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1. National Institute of Dental Research, Bethesda, MD (USA)

Corneal buttons were obtained from patients with types 1 and 2 macular corneal dystrophy (MCD) and from control patients with Fuchs' dystrophy or keratoconus. Buttons were incubated for 20 h in the presence of (3H)glucosamine or (2-3H)mannose. Radiolabeled proteoglycans and lactosaminoglycan-glycoproteins (L-GPs) were purified using chromatography on Q-Sepharose, Superose 6, and octyl-Sepharose. They were identified using chondroitinase ABC, keratanase or endo-beta-galactosidase digestion, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Superose 6 chromatography. This study confirms previous reports that type 1 MCD corneas synthesize a normal dermatan sulfate-proteoglycan (DS-PG) and an abnormal keratan sulfate-proteoglycan (KS-PG). The data indicate that typ 1 MCD corneas synthesize L-GP instead of KS-PG. This L-GP has a core protein of similar hydrophobicity (elution from octyl-Sepharose) and nearly similar mass (42 kDa) as the core protein of the KS-PG. It has identical glycoconjugates as those of the KS-PG except that they lack sulfate. Thus, type 1 MCD fails to synthesize keratan sulfate as a result of a defect in a sulfotransferase specific for sulfating lactosaminoglycans. Further, proteoglycans synthesized by a cornea from a patient with type 2 MCD were studied. This cornea synthesized a normal ratio of KS-PG to DS-PG although net synthesis of proteoglycans was approximately 30% below normal. The KS-PG appeared normal whereas the DS-PG had dermatan sulfate chains that were approximately 40% shorter than normal.

• OSTI ID: 6367192
• Journal Information: Journal of Biological Chemistry; (USA), Journal Name: Journal of Biological Chemistry; (USA) Vol. 265:26; ISSN JBCHA; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

550901* -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
AMINES
BIOSYNTHESIS
BODY
BODY AREAS
CARBOHYDRATES
CHROMATOGRAPHY
CORNEA
DISEASES
EYES
FACE
GLUCOSAMINE
GLYCOPROTEINS
HEAD
HEXOSAMINES
HEXOSES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
MANNOSE
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANS
PATHOGENESIS
PATIENTS
PROTEINS
SACCHARIDES
SENSE ORGANS
SENSE ORGANS DISEASES
SEPARATION PROCESSES
SYNTHESIS
TRACER TECHNIQUES
TRITIUM COMPOUNDS