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Fibrillin: evidence that chondroitin sulphate proteoglycans are components of microfibrils and associate with newly synthesised monomers
Author(s) -
Kielty Cay M.,
Whittaker Stephen P.,
Shuttleworth C.Adrian
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00423-1
Subject(s) - microfibril , fibrillin , chemistry , hyaluronidase , biochemistry , proteoglycan , chondroitin , staining , extracellular matrix , chondroitin sulphate , biophysics , glycosaminoglycan , cellulose , enzyme , biology , genetics
We have investigated the potential association of proteoglycans with intact fibrillin‐containing microfibrils from foetal bovine elastic tissues and with newly synthesised fibrillin in human and bovine cell cultures. Microfbril integrity was disrupted by chondroitinase ABC lyase and chondroitinase AC lyase, but not by keratanase or hyaluronidase. Following chondroitinase treatment, beads were disrupted but the underlying fibrillar scaffold appeared intact. Cuprolinic blue was prominently associated with beaded domains at a critical electrolyte concentration. Electron‐dense rods were often associated with cuprolinic blue‐treated microfbrils isolated from fixed tissues. Positive staining revealed charged foci at the beads. Newly synthesised fibrillin could be labelled with 35 S TransLabel, [ 3 H]glucosamine or 35 SO 4 but its electrophoretic mobility was not influenced by treatment with chondroitinase ABC or AC lyase. A diffuse 35 SO 4 ‐labelled chondroitinase‐sensitive component with a resistant band ( M r 35000) co‐immunoprecipitated with fibrillin. These experiments indicate that chondroitin sulphate proteoglycans associate with fibrillin and contribute to microfibril assembly. This association has major implications for microfibril function in health and disease.