Synthesis and evaluation of tripodal peptide analogues for cellular delivery of phosphopeptides.
Tripodal peptide analogues were designed on the basis of the phosphotyrosine binding pocket of the Src SH2 domain and assayed for their ability to bind to fluorescein-labeled phosphopeptides. Fluorescence polarization assays showed that a number of amphipathic linear peptide analogues (LPAs), such as LPA4, bind to fluorescein-labeled GpYEEI (F-GpYEEI). LPA4 was evaluated for potential application in cellular delivery of phosphopeptides. Fluorescence microimaging cellular uptake studies with fluorescein-attached LPA4 (F-LPA4) alone or with the mixture of LPA4 and F-GpYEEI in BT-20 cells showed dramatic increase of the fluorescence intensity in cytosol of cells, indicating that LPA4 can function as a delivery tool of F-GpYEEI across the cell membrane. Fluorescent flow cytometry studies showed the cellular uptake of F-LPA4 in an energy-independent pathway and confirmed the cellular uptake of F-GpYEEI in the presence of LPA4. These studies suggest that amphipathic tripodal peptide analogues, such as LPA4, can be used for cellular delivery of phosphopeptides.
Ye
Guofeng
G
Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA.
Nam
Nguyen-Hai
NH
Kumar
Anil
A
Saleh
Ali
A
Shenoy
Dinesh B
DB
Amiji
Mansoor M
MM
Lin
Xiaofeng
X
Sun
Gongqin
G
Parang
Keykavous
K
D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D003600:Cytosol / Q000378:metabolism; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D004560:Electricity; D005434:Flow Cytometry; D005454:Fluorescence Polarization; D006801:Humans; D008968:Molecular Conformation; D009994:Osmolar Concentration; D010456:Peptides, Cyclic / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D010748:Phosphopeptides / Q000737:chemistry / Q000378:metabolism*; D013329:Structure-Activity Relationship
D050091:Dendrimers; D004337:Drug Carriers; D010456:Peptides, Cyclic; D010748:Phosphopeptides