title: A multivalent ligand for the mannose-6-phosphate receptor for endolysosomal targeting of an activity-based probe.
abstract: The ubiquitously expressed mannose-6-phosphate receptors (MPRs) are a promising class of receptors for targeted compound delivery into the endolysosomal compartments of a variety of cell types. The development of a synthetic, multivalent, mannose-6-phosphate (M6P) glycopeptide-based MPR ligand is described. The conjugation of this ligand to fluorescent DCG-04, an activity-based probe for cysteine cathepsins, enabled fluorescent readout of its receptor-targeting properties. The resulting M6P-cluster-BODIPY-DCG-04 probe was shown to efficiently label cathepsins in cell lysates as well as in live cells. Furthermore, the introduction of the 6-O-phosphates leads to a completely altered uptake profile in COS and dendritic cells compared to a mannose-containing ligand. Competition with mannose-6-phosphate abolished all uptake of the probe in COS cells, and we conclude that the mannose-6-phosphate cluster targets the MPR and ensures the targeted delivery of cargo bound to the cluster into the endolysosomal pathway.
authors.affiliation: Bio-organic Synthesis, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2300 RA, Leiden (The Netherlands).
authors.forename: Sascha
authors.initials: S
authors.lastname: Hoogendoorn
authors.forename: Gijs H M
authors.initials: GH
authors.lastname: van Puijvelde
authors.forename: Johan
authors.initials: J
authors.lastname: Kuiper
authors.forename: Gijs A
authors.initials: GA
authors.lastname: van der Marel
authors.forename: Herman S
authors.initials: HS
authors.lastname: Overkleeft
mesh_terms: D000818:Animals; D001896:Boron Compounds / Q000737:chemistry; D019556:COS Cells; D002403:Cathepsins / Q000737:chemistry / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000737:chemistry; D006020:Glycopeptides / Q000138:chemical synthesis / Q000737:chemistry; D007930:Leucine / Q000031:analogs & derivatives / Q000737:chemistry; D008024:Ligands; D008360:Mannosephosphates / Q000737:chemistry; D051379:Mice; D011485:Protein Binding; D017527:Receptor, IGF Type 2 / Q000737:chemistry*
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; C419228:DCG 04; D005456:Fluorescent Dyes; D006020:Glycopeptides; D008024:Ligands; D008360:Mannosephosphates; D017527:Receptor, IGF Type 2; C027693:mannose-6-phosphate; D002403:Cathepsins; D007930:Leucine
keywords: activity-based protein profiling; drug delivery; endolysosomal pathway; fluorescent probes; mannose-6-phosphate