The Multifaceted Role of Glycosaminoglycans in the Cellular Uptake of Cell-Penetrating Peptides

Category
Intracellular Delivery of Nucleic Acids and Proteins
Year
2014
Authors
R. Wallbrecher, S. Schmidt, W. P. Verdurmen, P. H. Bovee-Geurts, F. Broecker,, A. Reinhardt,, T. H. van Kuppevelt, J. Eilander, S. Fanghänel, J. Bürck, P. Wadhwani, P. H. Seeberger,, A. S. Ulrich,, R. Brock
Institutions
Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud UniversityMedical Centre, 6525 GA Nijmegen, the Netherlands; Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, 14476 Potsdam, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany; Karlsruhe Institute of Technology (KIT), Institute for Organic Chemistry and CFN, 76131 Karlsruhe, Germany; KIT, Institute for Biological Interfaces (IBG-2), 76021 Karlsruhe, Germany
Summary

Here, we demonstrate that in spite of a general propensity to interact with CPPs the role of GAG in uptake varies greatly and depends on the nature of the CPP. For variants of a CPP derived from the human lactoferrin protein there was a negative correlation of the stoichiometry of GAG binding and uptake, indicating that GAG clustering promoted uptake. This CPP shares characteristics with other arginine rich CPP such as nonaarginine. In contrast, for analogs of the amphipathic transportan 10 (TP10) clustering impeded uptake. To monitor GAG clustering in living cells, metabolic labeling of sugars was employed. Here, cells are incubated with azido-bearing sugar analogs. Following incorporation into sialic acids, fluorescent labels can be introduced by click chemistry