Abstract
The mode of action of the sulfatases in the glycosaminoglycan metabolism is briefly reviewed. The evidences so far obtained suggest that there are three pathways of degradation of glycosaminoglycans involving several specific sulfatases with distinct modes of action. In mammals, and possibly in other vertebrates, the sulfatases act on a sequential order in concert with sugar hydrolases, removing sulfates from the nonreducing ends of the molecules in each cycle of degradation. In invertebrates, the sulfatases act directly upon the polymer producing extensive desulfation without need of concomitant depolymerization which takes place only on a second stage, by action of the sugar hydrolases. Finally, in bacteria, the sulfatases act only upon sulfated disaccharides and monosaccharides formed from the glycosaminoglycans by action of eliminases and glycuronidases. The biological role of the sulfatases on the recycling of sugars and sulfate is discussed.
