Tracking cellular localization of quantum dots-anchored peptide and glycopeptide with short-chain keto-functionalized poly-His-facilitated endosomal escape — ASN Events
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Tracking cellular localization of quantum dots-anchored peptide and glycopeptide with short-chain keto-functionalized poly-His-facilitated endosomal escape (#53)

Roger S. Tan 1 , Kentaro Naruchi 2 , Hiroshi Hinou 1 2 , Maho Amano 1 2 , Shin-Ichiro Nishimura 1 2
  1. Graduate School of Life Science and Research Center for Post-Genome Science and Technology, Hokkaido University, N21, W10, Kita-ku, Sapporo, Japan
  2. Medicinal Chemistry Pharmaceuticals Co. Ltd., N21, W12, Kita-ku, Sapporo, Japan

The insufficient ability of Quantum Dots (QDs) to traverse cell membrane and subsequent  endolysosomal sequestration hampered its intracellular delivery and molecular imaging uses1 . Therefore, developing a robust and nontoxic delivery method with prompt escape from endolysosomal entrapment is indispensable. Many endolysosomal escape molecules reported are cytotoxic, longer sequence and takes longer time facilitating an escape2 . We designed a facile and nontoxic cell penetrating peptide (CPP) that prevents endolysosomal QDs sequestration for tracing peptide (Pep) and glycopeptide (GP) intracellular fate. We believed that in cellular delivery of small molecules, these long and towering compounds may interfere in their intracellular recognition and thus may prevent them from reaching the exact cellular compartment where they supposed to be localized. We investigated the intracellular fate of GP and Pep using QDs by tracking their cellular localization through incorporation of simple and nontoxic short chain keto-functionalized polyhistidine (kpHis) and keto-functionalized polyarginine (kpArg), as endolysosome escape molecules, using self-assembled monolayers of aminooxy-functionalized monothiol group (ao-SH) as the linker and phosphorylcholine-type monothiol ligand (PC-SH) forming the conjugates kpHis-QD-GP/Pep and kpArg-QD-GP/Pep, respectively3 4 . The cellular uptake and localization of the conjugates were assessed using cell lines NHAC-Kn, A549, PC-3, HT-29 and HepG2. Endolysosomal sequestration was observed upon QDs' cytosolic  penetration. After kpHis- and kpArg- QDs conjugation, endolysosomal escape was observed after 2 hours of co-incubation. We observed that NHAC-Kn cells engulfed QDs in less than 5 minutes, while cancer cell lines showed slower uptake shown by the cell surface-bound QD fluorescence. However, kpArg-QD-GP/Pep conjugate showed aggregation in cell surface preventing it to traverse cytosol due perhaps to bigger aggregated size. The endolysosomal escape of kpHis-QD-GP/Pep, a noncytotoxic, was very efficient that the QD-GPs conjugates managed to reach the golgi apparatus after the escape. The specific functional roles of glycans attached to proteins/peptides will be discussed.

  1. X.Chen, A. Kis, A. Zettl, C. R. Bertozzi, Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 8218–8222.
  2. J. B. Delehanty, C. E. Bradburne, K. Boeneman, K. Susumu, D. Farrell, B. C. Mei, J. B. Blanco-Canosa, G. Dawson, P. E. Dawson, H. Mattoussi, and I. L. Medintz. Integr. Biol., 2010, 2, 265-277.
  3. T. Ohyanagi, N. Nagahori, K. Shimawaki, H. Hinou, T. Yamashita, A. Sasaki, T. Jin, T. Iwanaga, M. Kinjo and S-I. Nishimura, J. Am. Chem. Soc., 2011, 133, 12507–12517.
  4. H. Hoshi, K. Shimawaki, Y. Takegawa, T. Ohyanagi, M. Amano, H. Hinou and S-I. Nishimura, Biochem. et Biophys. Acta, 2012, 1820, 1391-1398.