has_handle has_reactive_group is_cleavable homofunctional cross-linker cleavable by MS2 labile bond biotin pentafluorophenyl BDRG 2 Biotin-aspartate-Rink-glycine cross-linker composed of a biotin affinity handle (B), a pentafluorophenyl (PFP) ester modified aspartate reside (D), a Rink group (R), and a PFP ester modified glycine reside (G). XLMOD XLMOD:02047