fractionation on deae-sepharose columns under two different sets of gradient elution conditions [ deae-i in which only acetate buffer was used ; or deae-ii in which acetate buffers were supplemented with 8 m urea ] identified two major classes of pg in both pap and ret cells - heparan sulfate proteoglycan ( hs-pg ) and chondroitin , dermatan sulfate proteoglycans ( cs , ds-pg ) - with an increased proportion of hs-pg in cells which had aged in vivo or in vitro ( late-passage cells also generate a low molecular weight component that resolves on these columns ) .
C0033692
pg
C0062503
hs-pg