PMID: 2496747Jan 24, 1989Paper

The acid-triggered entry pathway of Pseudomonas exotoxin A

Biochemistry
Z T Farahbakhsh, B J Wisnieski

Abstract

In this study we examined the pH requirements and reversibility of early events in the Pseudomonas toxin entry pathway, namely, membrane binding, insertion, and translocation. At pH 7.4, toxin binding to vesicles and insertion into the bilayer are very inefficient. Decreasing the pH greatly increases the efficiencies of these processes. Acid-treated toxin exhibits pH 7.4 binding and insertion levels. This indicates that hydrophobic regions that become exposed upon toxin acidficiation become buried again when the pH is raised to 7.4. In contrast, the change in toxin conformation that occurs upon membrane binding is irreversible. Returning samples to pH 7.4, incubation with excess toxin, or dilution with buffer up to 1000-fold leads to very little loss of bound toxin. Bound toxin exhibits an extremely high susceptibility to trypsin compared to free toxin (at both pH 4 and pH 7.4). At pH 4, membrane-associated toxin slowly proceeds to a trypsin-protected state; neutralization halts this process. At low pH, toxin was found to bind and insert into DMPC vesicles very efficiently at temperatures both above and below 23 degrees C, the lipid melting point. With fluid targets, the proportion of bound toxin that was photolabeled from with...Continue Reading

References

Jun 1, 1975·Proceedings of the National Academy of Sciences of the United States of America·B H Iglewski, D Kabat
Sep 1, 1978·Proceedings of the National Academy of Sciences of the United States of America·F Szoka, D Papahadjopoulos
Mar 1, 1985·Proceedings of the National Academy of Sciences of the United States of America·V L DavidsonW A Cramer
Apr 1, 1985·European Journal of Clinical Microbiology·C B SaelingerG Foertsch
Mar 1, 1986·Proceedings of the National Academy of Sciences of the United States of America·V S AlluredD B McKay
Mar 1, 1988·Proceedings of the National Academy of Sciences of the United States of America·H Lorberboum-GalskiI Pastan
Apr 1, 1986·Proceedings of the National Academy of Sciences of the United States of America·J M Zhao, E London
Jun 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·D J FitzGeraldI Pastan
Mar 1, 1971·Immunochemistry·M MorrisonR G Webster
May 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·G L GrayH L Heyneker
Oct 1, 1984·The Journal of Cell Biology·A R RobbinsI Mellman
Sep 1, 1983·Proceedings of the National Academy of Sciences of the United States of America·M MerionW S Sly
Apr 1, 1984·Journal of Cellular Physiology·A SundanS Olsnes
Jul 1, 1983·Molecular and Cellular Biology·J R DidsburyT J Moehring

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Citations

May 16, 2012·The Protein Journal·Supratim DeySaumen Datta
Mar 26, 1992·Biochimica Et Biophysica Acta·E London
Nov 1, 1992·Trends in Cell Biology·F G van der GootF Pattus
Nov 25, 2004·Progress in Biophysics and Molecular Biology·Michael W Parker, Susanne C Feil
Nov 18, 2000·Progress in Lipid Research·D C DrummondJ Leroux
Apr 1, 1990·Molecular Microbiology·M J WickB H Iglewski
Apr 5, 1992·Journal of Molecular Biology·M W ParkerD Tsernoglou
Sep 1, 1992·FEMS Microbiology Immunology·C MontecuccoO Rossetto

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