title: Synthesis and evaluation of tripodal peptide analogues for cellular delivery of phosphopeptides.
abstract: 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.
authors.affiliation: Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, Rhode Island 02881, USA.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Ye
authors.forename: Nguyen-Hai
authors.initials: NH
authors.lastname: Nam
authors.forename: Anil
authors.initials: A
authors.lastname: Kumar
authors.forename: Ali
authors.initials: A
authors.lastname: Saleh
authors.forename: Dinesh B
authors.initials: DB
authors.lastname: Shenoy
authors.forename: Mansoor M
authors.initials: MM
authors.lastname: Amiji
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lin
authors.forename: Gongqin
authors.initials: G
authors.lastname: Sun
authors.forename: Keykavous
authors.initials: K
authors.lastname: Parang
mesh_terms: 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
chemical_list: D050091:Dendrimers; D004337:Drug Carriers; D010456:Peptides, Cyclic; D010748:Phosphopeptides