MEDI 112 |
| A number of amphipathic peptides containing two arginine and one lysine residues were synthesized and evaluated for non-covalent cellular delivery of phosphopeptides. Fluorescence polarization assay showed that peptides containing long hydrophobic linkers, such as LPA4, can form a complex with the fluorescein-labeled GpYEEI (F-GpYEEI). LPA4 was further evaluated for potential application in cellular delivery of phosphopeptides to BT-20 live cells. Confocal microscopy and fluorescent flow cytometry studies with the mixture of LPA4 (50 μM) and F-GpYEEI (10 μM) in BT-20 cells showed dramatic increase in the fluorescence intensity in cytosol of cells after 30 minutes, suggesting that LPA4 can function as a delivery tool of F-GpYEEI. LPA1 was used as a negative control. LPA4 was not able to deliver other control peptides, F-AMpYSSV and F-GpYTKM, into the cells. These studies suggest that positively-charged amphipathic peptides can be used for non-covalent cellular delivery of specific phosphopeptides, and confirm our earlier results in the fixed cells.
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Poster Session
7:00 PM-9:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Medicinal Chemistry |
