[4)-beta-D-GlcpA-(1->4)-alpha-D-GlcpNAc6S-(1->4)-alpha-L-IdopA2S-(1->4)-alpha-D-GlcpN2,6S2-(1->4)-beta-D-GlcpA2S-(1->4)-alpha-D-GlcpN2,6S2-(1->4)-beta-D-GlcpA-(1->4)-?-?-GlcpN2,6S2-(1->]n