ABSTRACT
Two novel polyarginine labelled ruthenium polypyridyl dyes are reported, one conjugated to five, (Ru-Ahx-R5), and one to eight arginine residues, (Ru-Ahx-R8); both complexes exhibit long-lived, intense, and oxygen-sensitive luminescence; (Ru-R8) is passively, efficiently and very rapidly transported across the cell membrane into the cytoplasm without requirement for its permeablisation.
Subject(s)
Cell Membrane Permeability , Cell Membrane/metabolism , Multiple Myeloma/diagnosis , Oligopeptides/chemistry , Organometallic Compounds/metabolism , Pyridines/chemistry , Ruthenium/chemistry , Blood Platelets/cytology , Cytoplasm/metabolism , Fluorescent Dyes/chemistry , Humans , Luminescent Measurements , Molecular Structure , Multiple Myeloma/pathology , Organometallic Compounds/chemistry , Oxygen/chemistry , Structure-Activity Relationship , Tissue DistributionABSTRACT
Short synthetic oligopeptides based on regions of human proteins that encompass functional motifs are versatile reagents for understanding protein signaling and interactions. They can either mimic or inhibit the parent protein's activity and have been used in drug development. Peptide studies typically either derive peptides from a single identified protein or (at the other extreme) screen random combinatorial peptides, often without knowledge of the signaling pathways targeted. Our objective was to determine whether rational bioinformatic design of oligopeptides specifically targeted to potentially signaling-rich juxtamembrane regions could identify modulators of human platelet function. High-throughput in vitro platelet function assays of palmitylated cell-permeable oligopeptides corresponding to these regions identified many agonists and antagonists of platelet function. Many bioactive peptides were from adhesion molecules, including a specific CD226-derived inhibitor of inside-out platelet signaling. Systematic screens of this nature are highly efficient tools for discovering short signaling motifs in molecular signaling pathways.
