JBC, Vol. 250, Issue 18, 7251-7256, Sep, 1975
Variable nature of cartilage proteoglycans
P. Hoffman, T. A. Mashburn Jr, D. Hsu, D. Trivedi and J. Diep
Cartilage proteoglycan aggregates are separated from collagen and other
non-proteoglycan protein by preparative rate zonal sedimentation under
associative conditions. Dissociative rate zonal sedimentation produces
sedimented proteoglycan of lower protein content with a corresponding
increase in the amount of less sedimentable protein-rich proteoglycan. An
extensive number of sequential rate zonal sedimentations discloses that the
proceess of disaggregation involves the separation of proteoglycans varying
continuously in composition with no apparent discontinuities in
distribution to indicate the presence of distinctively different
macromolecules. The variations encompass proteoglycans of low protein
content containing less than 2% keratan sulfate and proteoglycans with
keratan sulfate as the predominant polysaccharide (present in
concentrations greater than 2-fold that of the chondroitin sulfate) and
more than a 10-fold increase in protein content.