67Ga binding to sulfated proteoglycan in normal and CCl4-damaged liver

The binding of 67Ga and 59Fe to sulfated proteoglycan in the normal and CCl4-damaged mouse livers have been studied by means of Sepharose CL-4B column chromatography in guanidine hydrochloride. 67Ga uptake in the liver was elevated to approximately 1.8 times that of the control 2 days after a single administration of CCl4. 67Ga was bound to two types of sulfated proteoglycan (average mol. wt 1,700,000 and 35,000) in the normal and CCl4-damaged liver. However, the percentage of 67Ga bound to sulfated proteoglycan (mol. wt about 1,700,000) in the CCl4-damaged liver was increased as compared with that in the normal liver. Papain digestion of these sulfated proteoglycan fractions caused the 67Ga radioactivities to shift to a low molecular weight fraction (about 10,000). Cellulose acetate electrophoresis of this fraction (mol. wt about 10,000) isolated from the normal and CCl4-damaged livers resulted in identifying heparan sulfate (HS). The 35SO4 incorporation into HS band isolated from the CCl4-damaged liver, as an indicator of HS synthesis, was increased compared with that of the normal liver. 59Fe was not bound to sulfated proteoglycan and its gel filtration pattern was evidently different from that of 67Ga.