Degrades heparin and heparan sulfate. Eliminative cleavage of polysaccharides containing (1->4)-linked D-glucuronate or L-iduronate residues and (1->4)-alpha-linked 2-sulfoamino-2-deoxy-6-sulfo-D-glucose residues to give oligosaccharides with terminal 4-deoxy-alpha-D-gluc-4-enuronosyl groups at their non-reducing ends. Inhibited by Cu(2+) ion, lead and some agents that modify histidine and cysteine residues. Activated by KCl and by reducing agents, such as dithiothreitol and 2-mercaptoethanol. Optimum pH is 7.2. Optimum temperature is 45 degrees Celsius. The N-terminus is blocked.