title: Structure-activity relationship of truncated and substituted analogues of the intracellular delivery vector Penetratin.
abstract: Peptides derived from the third alpha-helix of the homeodomain (residues 43-58; Penetratin) of Antennapedia, a Drosophila homeoprotein, were prepared by simultaneous multiple synthesis. Sets of N- and C-terminally truncated peptides, as well as a series of alanine substitution analogues, were studied. Cell penetration assays using human cell cultures with these peptides revealed that the C-terminal segment 52Arg-Arg-Met-Lys-Trp-Lys-Lys58 of the parent sequence was necessary and sufficient for efficient cell membrane translocation. Individual Ala substitutions of the peptide's basic residues led to markedly decreased cell internalization ability, whereas replacement of hydrophobic residues was tolerated surprisingly well. Subcellular localization was seen to be affected by substitutions, with analogues being addressed preferentially to the cytosol or to the nucleus. Conformational constriction of the Penetratin sequence through placement and oxidation of flanking cysteine residues afforded a cyclic disulfide peptide which had lost most of its membrane translocation capacity.
authors.affiliation: Cyclacel Limited, Dundee, UK. pfischer@cyclacel.com
authors.forename: P M
authors.initials: PM
authors.lastname: Fischer
authors.forename: N Z
authors.initials: NZ
authors.lastname: Zhelev
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: J E
authors.initials: JE
authors.lastname: Melville
authors.forename: R
authors.initials: R
authors.lastname: Fåhraeus
authors.forename: D P
authors.initials: DP
authors.lastname: Lane
mesh_terms: D051943:Antennapedia Homeodomain Protein; D001692:Biological Transport; D002451:Cell Compartmentation; D002467:Cell Nucleus; D002478:Cells, Cultured; D003600:Cytosol; D004337:Drug Carriers / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D018398:Homeodomain Proteins / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008968:Molecular Conformation; D009687:Nuclear Proteins; D009842:Oligopeptides / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014157:Transcription Factors
chemical_list: D051943:Antennapedia Homeodomain Protein; D004337:Drug Carriers; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D009842:Oligopeptides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D014157:Transcription Factors