IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Moayeri, M
Right arrow Articles by Welch, R A
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Moayeri, M
Right arrow Articles by Welch, R A

 Previous Article  |  Next Article 

Infection and Immunity, October 1994, p. 4124-4134, Vol. 62, No. 10
0019-9567/1994/$04.00+0     DOI:

research-article

Effects of temperature, time, and toxin concentration on lesion formation by the Escherichia coli hemolysin.

M Moayeri and R A Welch

Department of Medical Microbiology and Immunology, University of Wisconsin Medical School, Madison 53706.

ABSTRACT

We performed osmotic protection experiments to test the hypothesis that the Escherichia coli hemolysin forms a discrete-size pore in erythrocyte membranes. The effects of toxin concentration, assay time, temperature, and protectant concentrations were examined. The results we present here raise doubts about the existing model of pore formation by hemolysin. We demonstrate that osmotic protection by various sugars of different sizes is a function of hemolysin concentration and assay time. The data indicate that under various conditions, lesion sizes with a diameter ranging from < 0.6 to > 1.2 nm can be inferred. Quantification of hemolysin permitted the estimation of the number of HlyA structural protein molecules required per erythrocyte for lysis in the presence of each protectant. It appears that hemolysin induces heterogeneous erythrocyte lesions which increase in size over time. Influx experiments utilizing radioactive sugar markers indicated that time-dependent osmotic protection patterns are independent of the diffusion rates of individual protectants. We demonstrate that the rate of the putative growth in the size of hemolysin-mediated lesions is temperature dependent. The erythrocyte membrane lesions formed at 37 degrees C can be stabilized in size when shifted to 4 degrees C. On the basis of these data, new models for the nature of the hemolysin-mediated erythrocyte membrane lesions are presented.

Infection and Immunity, October 1994, p. 4124-4134, Vol. 62, No. 10
0019-9567/1994/$04.00+0     DOI:




This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1994 by the American Society for Microbiology. All rights reserved.