title: Keratoconus: I. Biochemical studies.
abstract: The present study analyses collagenous and non-collagenous components from age-matched normal and keratoconus corneas. Intact keratoconus corneas showed decreased collagen, total protein, and hydroxylysine levels, with normal reducible collagen cross-linking. Non-collagenous fractions were isolated from corneas with a 4 M guanidine procedure. As demonstrated by PAGE-silver stain, the keratoconus cornea guanidine extracts had a 75 kDa band that was absent in normal cornea guanidine extracts. In addition, there was a markedly increased level of protein, uronic acid and neutral hexose in keratoconus extracts as compared with controls. Our Western blot studies showed increased affinity for the castor-bean agglutinin (RCA120, specific for terminal galactose) in the keratoconus extracts as compared with normals. These data suggest the presence of an abnormal noncollagenous component in keratoconus corneas.
authors.affiliation: Department of Nutrition, University of California, Davis 95616.
authors.forename: J W
authors.initials: JW
authors.lastname: Critchfield
authors.forename: A J
authors.initials: AJ
authors.lastname: Calandra
authors.forename: A B
authors.initials: AB
authors.lastname: Nesburn
authors.forename: M C
authors.initials: MC
authors.lastname: Kenney
mesh_terms: D000328:Adult; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D006801:Humans; D006901:Hydroxylysine / Q000378:metabolism; D006909:Hydroxyproline / Q000378:metabolism; D007640:Keratoconus / Q000378:metabolism*; D037102:Lectins; D008875:Middle Aged; D014574:Uronic Acids / Q000378:metabolism
chemical_list: D005136:Eye Proteins; D006601:Hexoses; D037102:Lectins; D014574:Uronic Acids; D006901:Hydroxylysine; D003094:Collagen; D003545:Cysteine; D006909:Hydroxyproline