The amino acids ofEscherichia colienterotoxin B subunit involved in binding to Bio-Gel A-5m or to the glycoprotein from mouse intestinal epithelial cells

1996 ◽  
Vol 42 (10) ◽  
pp. 983-988 ◽  
Author(s):  
Hidetsugu Kawase ◽  
Michio Kato ◽  
Seizi Imamura ◽  
Takao Tsuji ◽  
Akio Miyama
Keyword(s):  
Amino Acids ◽  
Cholera Toxin ◽  
Intestinal Epithelial Cells ◽  
Intestinal Cells ◽  
Intestinal Epithelial ◽  
Amino Acid Residues ◽  
Binding Ability ◽  
B Subunit ◽  
Heat Labile ◽  
Enterotoxin B

We determined whether Arg13, Met31, and Ser95 of the heat-labile enterotoxin B subunit (LT-B) might be involved in Lt-B binding to oligosaccharides, which did not bind to the B subunit of the cholera toxin (CT-B). Three LT-B mutants, R13H, M31L, and S95A were prepared by substituting three amino acid residues that differ in CT-B. These mutants formed a pentamer and exhibited the same binding ability to the GM1ganglioside as native LT-B. Although these mutants did not bind to Bio-Gel A-5m, they did bind to the glycoprotein from mouse intestinal cells in the order R13H > M31L > S95A. These data suggest that Ser95, Met31, and Arg13 are important for LT-B binding to Bio-Gel A-5m, and that although Ser95 is also partially responsible for LT-B binding to the glycoprotein, Arg13 has no significant involvement in it.Key words: heat-labile enterotoxin, cholera toxin, Bio-Gel A-5m, glycoprotein.

scholarly journals Escherichia coli Heat-Labile Enterotoxin B Subunit Is a More Potent Mucosal Adjuvant than Its Closely Related Homologue, the B Subunit of Cholera Toxin

2001 ◽  
Vol 69 (5) ◽  
pp. 3476-3482 ◽  
Author(s):  
Douglas G. Millar ◽  
Timothy R. Hirst ◽  
Denis P. Snider
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Lymphocyte Proliferation ◽  
Vaccine Adjuvants ◽  
B Subunit ◽  
Heat Labile ◽  
Antibody Titers ◽  
Enterotoxin B ◽  
Draining Lymph Nodes ◽  
Stimulation Of

ABSTRACT Although cholera toxin (Ctx) and Escherichia coliheat-labile enterotoxin (Etx) are known to be potent mucosal adjuvants, it remains controversial whether the adjuvanticity of the holotoxins extends to their nontoxic, receptor-binding B subunits. Here, we have systematically evaluated the comparative adjuvant properties of highly purified recombinant EtxB and CtxB. EtxB was found to be a more potent adjuvant than CtxB, stimulating responses to hen egg lysozyme when the two were coadministered to mice intranasally, as assessed by enhanced serum and secretory antibody titers as well as by stimulation of lymphocyte proliferation in spleen and draining lymph nodes. These results indicate that, although structurally very similar, EtxB and CtxB have strikingly different immunostimulatory properties and should not be considered equivalent as prospective vaccine adjuvants.

Interaction of Cholera Toxin B Subunit with Rat Intestinal Epithelial Cells

2018 ◽  
Vol 44 (4) ◽  
pp. 403-407
Author(s):  
E. V. Navolotskaya ◽  
V. B. Sadovnikov ◽  
D. V. Zinchenko ◽  
V. I. Vladimirov ◽  
Y. A. Zolotarev
Keyword(s):  
Epithelial Cells ◽  
Cholera Toxin ◽  
Intestinal Epithelial Cells ◽  
Cholera Toxin B Subunit ◽  
Intestinal Epithelial ◽  
Toxin B ◽  
Cholera Toxin B ◽  
B Subunit

Binding of cholera toxin B subunit to intestinal epithelial cells

2018 ◽  
Vol 47 ◽  
pp. 269-273 ◽  
Author(s):  
Elena V. Navolotskaya ◽  
Vladimir B. Sadovnikov ◽  
Valery M. Lipkin ◽  
Vladimir P. Zav'yalov
Keyword(s):  
Epithelial Cells ◽  
Cholera Toxin ◽  
Intestinal Epithelial Cells ◽  
Cholera Toxin B Subunit ◽  
Intestinal Epithelial ◽  
Toxin B ◽  
Cholera Toxin B ◽  
B Subunit

Ingestion of transgenic carrots expressing the Escherichia coli heat-labile enterotoxin B subunit protects mice against cholera toxin challenge

2007 ◽  
Vol 27 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Sergio Rosales-Mendoza ◽  
Ruth Elena Soria-Guerra ◽  
Rubén López-Revilla ◽  
Leticia Moreno-Fierros ◽  
Ángel Gabriel Alpuche-Solís
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
B Subunit ◽  
Heat Labile ◽  
Enterotoxin B

Interaction of cholera toxin and Escherichia coli enterotoxin with isolated intestinal epithelial cells

1984 ◽  
Vol 247 (6) ◽  
pp. G623-G631 ◽  
Author(s):  
C. S. Hyun ◽  
G. A. Kimmich
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Cholera Toxin ◽  
Intestinal Epithelial Cells ◽  
Biologically Active ◽  
Small Contribution ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
B Subunit ◽  
Dose Dependent

The interaction of biologically active 125I-labeled cholera toxin with isolated chick intestinal epithelial cells involves a large number (approx 1.7 10(6)/cell) of high-affinity (Kd = 8–9 X 10(-9) M) binding sites that belong to a single class. Binding of iodotoxin to the cells occurs rapidly, is half-maximal within 1 min, and is complete in 3–7 min (at 37 degrees C) depending on the toxin concentration. Toxin binding is saturable and includes only a small contribution from nonspecific sites. Ligand competition studies suggest that the isolated B subunit of choleragen (CT-B) behaves in an almost identical fashion to the holotoxin (CT), whereas the A subunit shows no detectable activity in competitive binding. Assays for cAMP indicate that neither that A nor the B subunits of CT contain any activity for increasing the level of intracellular cAMP. B subunit, when incubated with CT, inhibits CT-induced elevation of cAMP in a dose-dependent manner. Preincubation of 125I-CT with various concentrations of ganglioside GM1 also shows a dose-dependent inhibitory effect on the binding activity of the toxin. Pretreatment of CT with increasing concentrations of GM1 results in a progressive decrease in toxin-induced formation of cAMP. Escherichia coli heat-labile enterotoxin, which is known to alter intestinal function via a mechanism similar to that of CT, has binding and biological effects very similar to thoseof CT.

scholarly journals Mutational Analysis of Ganglioside GM1-Binding Ability, Pentamer Formation, and Epitopes of Cholera Toxin B (CTB) Subunits and CTB/Heat-Labile Enterotoxin B Subunit Chimeras

2002 ◽  
Vol 70 (3) ◽  
pp. 1260-1271 ◽  
Author(s):  
Michael G. Jobling ◽  
Randall K. Holmes
Keyword(s):  
Cholera Toxin ◽  
Mutational Analysis ◽  
Single Amino Acid ◽  
Cholera Toxin B Subunit ◽  
Toxin B ◽  
Cholera Toxin B ◽  
B Subunit ◽  
Heat Labile ◽  
Enterotoxin B

ABSTRACT Variants of cholera toxin B subunit (CTB) were made by bisulfite- and oligonucleotide-directed mutagenesis of the ctxB gene. Variants were screened by a radial passive immune hemolysis assay (RPIHA) for loss of binding to sheep erythrocytes (SRBC). Variant CTBs were characterized for the formation of immunoreactive pentamers, the ability to bind ganglioside GM1 in vitro, and reactivity with a panel of monoclonal anti-CTB antibodies. Substitutions at eight positions (i.e., positions 22, 29, 36, 45, 64, 86, 93, and 100) greatly reduced the yield of immunoreactive CTB. RPIHA-negative substitution variants that formed immunoreactive pentamers were obtained for residues 12, 33, 36, 51, 52 + 54, 91, and 95. Tyrosine-12 was identified as a novel residue important for GM1 binding since, among all of the novel variants isolated with altered RPIHA phenotypes, only CTB with aspartate substituted for tyrosine at position 12 failed to bind significantly to ganglioside GM1 in vitro. In contrast, CTB variants with single substitutions for several other residues (Glu-51, Lys-91, and Ala-95) that participate in GM1 binding, based on the crystal structure of CTB and the oligosaccharide of GM1, were not appreciably altered in their ability to bind GM1 in vitro, even though they showed altered RPIHA phenotypes and did not bind to SRBC. Hybrid B genes made by fusing ctxB and the related Escherichia coli heat-labile enterotoxin eltB genes at codon 56 produced CTB variants that had 7 or 12 heat-labile enterotoxin B residue substitutions in the amino or carboxyl halves of the monomer, respectively, each of which which also bound GM1 as well as wild-type CTB. This collection of variant CTBs in which 47 of the 103 residues were substituted was used to map the epitopes of nine anti-CTB monoclonal antibodies (MAbs). Each MAb had a unique pattern of reactivity with the panel of CTB variants. Although no two of the epitopes recognized by different MAbs were identical, most of the single amino acid substitutions that altered the immunoreactivity of CTB affected more that one epitope. The tertiary structures of the epitopes of these anti-CTB MAbs are highly conformational and may involve structural elements both within and between CTB monomers. Substitution of valine for alanine at positions 10 and 46 had dramatic effects on the immunoreactivity of CTB, affecting epitopes recognized by eight or six MAbs, respectively.

Construction of plasmids useful for production of the B subunit of cholera toxin fromVibrio cholerae or a heat-labile enterotoxin from enterotoxigenicEscherichia coli

1994 ◽  
Vol 10 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Takao Tsuji ◽  
Michio Kato ◽  
Yutaka Kato ◽  
Hidetsugu Kawase ◽  
Seizi Imamura ◽  
...  
Keyword(s):  
Cholera Toxin ◽  
B Subunit ◽  
Heat Labile
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