Interaction of immunologically-active lipopeptides with membranes
| Autor: | Bernd Wille, Joerg Metzger, Günther Jung, L. Biesert, Wolfgang G. Bessler, William H. Sawyer |
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| Rok vydání: | 1993 |
| Předmět: |
Models
Molecular Molecular Sequence Data Biophysics Synthetic membrane Peptide Biochemistry Cell membrane Sonication chemistry.chemical_compound Phosphatidylcholine Tumor Cells Cultured medicine Fluorescence microscope Amino Acid Sequence Cysteine chemistry.chemical_classification B-Lymphocytes Escherichia coli Proteins Vesicle Cell Membrane Fatty Acids Electron Spin Resonance Spectroscopy Lipopeptide Cell Biology Flow Cytometry medicine.anatomical_structure Membrane chemistry Mitogens Carrier Proteins Peptides Fluorescein-5-isothiocyanate Bacterial Outer Membrane Proteins |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1149:29-39 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/0005-2736(93)90021-q |
| Popis: | Synthetic tripalmitoyl-S-glycerylcysteinyl (Pam3Cys) peptides are derived from the N-terminal part of bacterial lipoprotein and constitute polyclonal B-lymphocyte and macrophage activators. In order to elucidate the primary events of leukocyte activation, we investigated the biophysical interaction of lipopeptides containing spin labels or fluorescent markers with phosphatidylcholine vesicles or immune cells. Utilizing fluorescence microscopy and FACS analysis we found, that the surface of cells, after incubation with a fluorescein-labelled lipopeptide, was highly fluorescent. In addition, capping and patching was observed. Furthermore, fluorescence quenching experiments and electron paramagnetic resonance studies using vesicles incubated with lipopeptides suggested, that the peptide moiety and other more polar molecules linked to the lipo-amino acid are exposed to the hydrophilic compartment. These results show that in lipopeptide conjugates the Pam3Cys moiety acts as an efficient membrane anchor for molecules covalently coupled to it. The sequestering of the fatty-acid chains of the lipopeptide within the membrane is an early step of interaction, which might induce the uptake of the lipopeptide into the cell and the stimulation of immunocompetent cells. |
| Databáze: | OpenAIRE |
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