This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Clements, J D Articles by Finkelstein, R A Search for Related Content PubMed PubMed Citation Articles by Clements, J D Articles by Finkelstein, R A

Isolation and characterization of homogeneous heat-labile enterotoxins with high specific activity from Escherichia coli cultures.

ABSTRACT

The heat-labile enterotoxin (LT) has been isolated in homogeneous form with high specific activity from three sources: cell-free supernatant, NaCl extract, and whole-cell lysates of an enterotoxigenic Escherichia coli strain. In vitro immunological assays were used in lieu of tedious and highly variable bioassays to recognize fractions with activity. This revealed that the major portion of the LT remained adherent to columns containing agarose, from which it could be eluted quantitatively in practically homogeneous form by galactose. Isolated LT has remarkable similarities to the cholera enterotoxin (choleragen) in both subunit structure and amino acid composition, although there are also notable differences in these two enterotoxins, which are related immunologically and by mode of action. Unlike choleragen, in which the A region is totally nicked, E. coli LT, depending on its source, is activated by proteolytic processing. The activity of LT is equivalent to that of choleragen in bioassays on adrenal cells, in rabbit skin, and in rabbit ileal loops, especially when, depending on the source of material, the LT has been activated by treatment with trypsin. The whole-cell lysate is the richest source of LT.

This article has been cited by other articles:

• Banerjee, S, Medina-Fatimi, A, Nichols, R, Tendler, D, Michetti, M, Simon, J, Kelly, C P, Monath, T P, Michetti, P (2002). Safety and efficacy of low dose Escherichia coli enterotoxin adjuvant for urease based oral immunisation against Helicobacter pylori in healthy volunteers. Gut 51: 634-640 [Abstract] [Full Text]  
• Horstman, A. L., Kuehn, M. J. (2002). Bacterial Surface Association of Heat-labile Enterotoxin through Lipopolysaccharide after Secretion via the General Secretory Pathway. J. Biol. Chem. 277: 32538-32545 [Abstract] [Full Text]  
• Arrington, J., Braun, R. P., Dong, L., Fuller, D. H., Macklin, M. D., Umlauf, S. W., Wagner, S. J., Wu, M. S., Payne, L. G., Haynes, J. R. (2002). Plasmid Vectors Encoding Cholera Toxin or the Heat-Labile Enterotoxin from Escherichia coli Are Strong Adjuvants for DNA Vaccines. J. Virol. 76: 4536-4546 [Abstract] [Full Text]  
• Kotloff, K. L., Sztein, M. B., Wasserman, S. S., Losonsky, G. A., DiLorenzo, S. C., Walker, R. I. (2001). Safety and Immunogenicity of Oral Inactivated Whole-Cell Helicobacter pylori Vaccine with Adjuvant among Volunteers with or without Subclinical Infection. Infect. Immun. 69: 3581-3590 [Abstract] [Full Text]  
• Bowman, C. C., Clements, J. D. (2001). Differential Biological and Adjuvant Activities of Cholera Toxin and Escherichia coli Heat-Labile Enterotoxin Hybrids. Infect. Immun. 69: 1528-1535 [Abstract] [Full Text]  
• Sathyamoorthy, V., Hall, R. H., McCardell, B. A., Kothary, M. H., Ahn, S. J., Ratnayake, S. (2000). Purification and Characterization of a Cytotonic Protein Expressed In Vitro by the Live Cholera Vaccine Candidate CVD 103-HgR. Infect. Immun. 68: 6062-6065 [Abstract] [Full Text]  
• Mourad, F H, Nassar, C F (2000). Effect of vasoactive intestinal polypeptide (VIP) antagonism on rat jejunal fluid and electrolyte secretion induced by cholera and Escherichia coli enterotoxins. Gut 47: 382-386 [Abstract] [Full Text]  
• Horstman, A. L., Kuehn, M. J. (2000). Enterotoxigenic Escherichia coli Secretes Active Heat-labile Enterotoxin via Outer Membrane Vesicles. J. Biol. Chem. 275: 12489-12496 [Abstract] [Full Text]  
• McNeal, M. M., Rae, M. N., Bean, J. A., Ward, R. L. (1999). Antibody-Dependent and -Independent Protection following Intranasal Immunization of Mice with Rotavirus Particles. J. Virol. 73: 7565-7573 [Abstract] [Full Text]  
• Ryan, E. T., Crean, T. I., John, M., Butterton, J. R., Clements, J. D., Calderwood, S. B. (1999). In Vivo Expression and Immunoadjuvancy of a Mutant of Heat-Labile Enterotoxin of Escherichia coli in Vaccine and Vector Strains of Vibrio cholerae. Infect. Immun. 67: 1694-1701 [Abstract] [Full Text]  
• Cardenas-Freytag, L., Cheng, E., Mayeux, P., Domer, J. E., Clements, J. D. (1999). Effectiveness of a Vaccine Composed of Heat-Killed Candida albicans and a Novel Mucosal Adjuvant, LT(R192G), against Systemic Candidiasis. Infect. Immun. 67: 826-833 [Abstract] [Full Text]  
• O'Neal, C. M., Clements, J. D., Estes, M. K., Conner, M. E. (1998). Rotavirus 2/6 Viruslike Particles Administered Intranasally with Cholera Toxin, Escherichia coli Heat-Labile Toxin (LT), and LT-R192G Induce Protection from Rotavirus Challenge. J. Virol. 72: 3390-3393 [Abstract] [Full Text]  
• Neill, R., Ivins, B., Holmes, R. (1983). Synthesis and secretion of the plasmid-coded heat-labile enterotoxin of Escherichia coli in Vibrio cholerae. Science 221: 289-291 [Abstract]