Identification and Action Patterns of Two Chondroitin Sulfate Sulfatases From a Marine Bacterium sp. QA16.

Chondroitin sulfate (CS)/dermatan sulfate (DS) is a kind of sulfated polyanionic, linear polysaccharide belonging to glycosaminoglycan. CS/DS sulfatases, which specifically hydrolyze sulfate groups from CS/DS oligo-/polysaccharides, are potential tools for structural and functional studies of CD/DS. However, only a few sulfatases have been reported and characterized in detail to date. In this study, two CS/DS sulfatases, PB_3262 and PB_3285, were identified from the marine bacterium sp. QA16 and their action patterns were studied in detail. PB_3262 was characterized as a novel 4--endosulfatase that can effectively and specifically hydrolyze the 4--sulfate group of disaccharide GlcUAβ1-3GalNAc(4--sulfate) but not GlcUAβ1-3GalNAc(4,6--sulfate) and IdoUAα1-3GalNAc(4--sulfate) in CS/DS oligo-/polysaccharides, which is very different from the identified 4--endosulfatases in the substrate profile. In contrast, PB_3285 specifically hydrolyzes the 6--sulfate groups of GalNAc(6--sulfate) residues located at the reducing ends of the CS chains and is the first recombinantly expressed 6--exosulfatase to effectively act on CS oligosaccharides.