Endoglycosidase that cleaves heparan sulfate proteoglycans (HSPGs) into heparan sulfate side chains and core proteoglycans. Participates in extracellular matrix (ECM) degradation and remodeling. Selectively cleaves the linkage between a glucuronic acid unit and an N-sulfo glucosamine unit carrying either a 3-O-sulfo or a 6-O-sulfo group. Can also cleave the linkage between a glucuronic acid unit and an N-sulfo glucosamine unit carrying a 2-O-sulfo group, but not linkages between a glucuronic acid unit and a 2-O-sulfated iduronic acid moiety (By similarity). Increases cell adhesion to the extracellular matrix (ECM), independent of its enzymatic activity. endohydrolysis of (1->4)-beta-D-glycosidic bonds of heparan sulfate chains in heparan sulfate proteoglycan. Heterodimer; the active enzyme is a heterodimer of the 60 kDa and 45 kDa proteolytic products. Localized close to cell surface. Expressed, as early as 12 hours post fertilization, in cells migrating from the epiblast and forming the hypoblast layer. Later on at 72 h, preferentially expressed in cells of the developing vascular and nervous systems. N-glycosylated. Proteolytically cleaved to produce a 60 kDa and a 45 kDa product. Belongs to the glycosyl hydrolase 79 family.