[Components of proteoglycan aggregates in human hyaline cartilage]

The components of proteoglycan aggregates--proteoglycan subunits and link proteins from articular cartilage extracts of newborns--were isolated and purified. The content of extracted uronic acids and protein per 1 g of wet weight was 4.77 +/- 0.52 and 3.19 +/- 0.14 mg, respectively. The components of proteoglycan aggregates were isolated and purified by caesium chloride density gradient ultracentrifugation under association and dissociation conditions, as well as by gel filtration on Sephacryl S-200. The uronic acids/protein ratio for proteoglycan subunits was equal to 59.13 +/- 10.19, their relative electrophoretic mobility was 0.54 +/- 0.01 (the mobility of the chondroitin sulfate was taken for unity). The IR spectra of proteoglycan subunits were characterized. Three link proteins with Mr 48 000, 44 000 and 41 500 were isolated from proteoglycan aggregates and characterized. The protein with Mr 48 000 was predominant.