The Journal of biological chemistry, 1994-03, Vol.269 (11), p.8402-8407
1994
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Details
- Autor(en) / Beteiligte
- Titel
- Inhibition of membrane translocation of diphtheria toxin A-fragment by internal disulfide bridges
- Ist Teil von
- The Journal of biological chemistry, 1994-03, Vol.269 (11), p.8402-8407
- Ort / Verlag
- Bethesda, MD: American Society for Biochemistry and Molecular Biology
- Erscheinungsjahr
- 1994
- Quelle
- MEDLINE
- Beschreibungen/Notizen
- Fragment A of diphtheria toxin is translocated to the cytosol when the toxin is presented to receptor-positive cells. The toxin binds to cell surface receptors through its B-fragment, and after endocytotic uptake, the low endosomal pH triggers translocation of the A-fragment across the membrane. Translocation can also be induced at the level of the plasma membrane by exposure to low pH medium. Based on the diphtheria toxin crystal structure, we made five double cysteine mutants of the A-fragment, each expected to form an intramolecular disulfide bond. Four of the double cysteine mutants efficiently formed an intramolecular disulfide bridge, and these same mutants showed a strong reduction in their translocating ability. The inhibition of translocation was observed both when the toxin was endocytosed and when translocation was induced by exposing surface-bound toxin to low pH. The data indicate that extensive unfolding of the A-fragment is required for translocation.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0021-9258eISSN: 1083-351XDOI: 10.1016/s0021-9258(17)37208-3Titel-ID: cdi_proquest_miscellaneous_16898264
- Format
- –
- Schlagworte
- Adenosine Diphosphate Ribose - metabolism, Animals, Bacteriology, Base Sequence, Binding Sites, Biological and medical sciences, Cell Membrane - metabolism, Cell Survival - drug effects, Cloning, Molecular, Corynebacterium diphtheriae, Cysteine, Diphtheria Toxin - chemistry, Diphtheria Toxin - metabolism, Diphtheria Toxin - toxicity, Disulfides - metabolism, DNA Primers, Electrophoresis, Polyacrylamide Gel, Escherichia coli, Fundamental and applied biological sciences. Psychology, Kinetics, Microbiology, Models, Molecular, Molecular Sequence Data, Mutagenesis, Site-Directed, NAD - metabolism, Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains, Peptide Fragments - chemistry, Peptide Fragments - metabolism, Peptide Fragments - toxicity, Protein Biosynthesis, Protein Structure, Secondary, Recombinant Proteins - chemistry, Recombinant Proteins - metabolism, Recombinant Proteins - toxicity, Transcription, Genetic, Vero Cells