Altered composition and metabolism of proteoglycans isolated from degenerated human articular cartilage
Musilová, J.; Musil, J.; Susta, A.
Acta Universitatis Carolinae. Medica 22(1-2): 19-25
1976
ISSN/ISBN: 0001-7116 PMID: 1020712 Document Number: 99337
A detailed chemical analysis was performed with fractions of proteoglycans obtained by CsCl density centrifugation after previous extraction with 4 M guanidinium hydrochloride from normal and degenerated human articular cartilage. A distinct reduction of protein and hexosamine content was found in a fraction corresponding to the link glycoprotein from the arthrotic cartilage. The incorporation of glucosamine-1-14C and leucine-3H was investigated in cartilage slices withdrawn from the borderline of total lesion and from the macroscopically normal adjacent tissue. In normal tissue, the highest rate of incorporation was found in the fraction corresponding to link glycoprotein; in the degenerate cartilage, the incorporation of both precursors was oriented mainly into the fraction corresponding to proteoglycan monomers. The results are discussed from the viewpoint of a tentatively increased rate of proteoglycan monomers biosynthesis in arthrotic cartilage. These monomers, not having the ability for further aggregation (caused by lack of link glycoprotein) may be easily broken down by the action of proteolytic and other hydrolytic enzymes.