The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism

M. Sukumar, Jose Rizo-Rey, M. Wall, L. A. Dreyfus, Y. M. Kupersztoch, L. M. Gierasch

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The heat-stable enterotoxin b (STb) is secreted by enterotoxigenic Escherichia coli that cause secretory diarrhea in animals and humans. It is a 48-amino acid peptide containing two disulfide bridges, between residues 10 and 48 and 21 and 36, which are crucial for its biological activity. Here, we report the solution structure of STb determined by two- and three-dimensional NMR methods. Approximate interproton distances derived from NOE data were used to construct structures of STb using distance-geometry and simulated annealing procedures. The NMR-derived structure shows that STb is helical between residues 10 and 22 and residues 38 and 44. The helical structure in the region 10-22 is amphipathic and exposes several polar residues to the solvent, some of which have been shown to be important in determining the toxicity of STb. The hydrophobic residues on the opposite face of this helix make contacts with the hydrophobic residues of the C-terminal helix. The loop region between residues 21 and 36 has another cluster of hydrophobic residues and exposes Arg 29 and Asp 30, which have been shown to be important for intestinal secretory activity. CD studies show that reduction of disulfide bridges results in a dramatic loss of structure, which correlates with loss of function. Reduced STb adopts a predominantly random-coil conformation. Chromatographic measurements of concentrations of native, fully reduced, and single disulfide species in equilibrium mixture of STb in redox buffers indicate that the formation of the two disulfide bonds in STb is only moderately cooperative. Similar measurements in the presence of 8 M urea suggest that the native secondary structure significantly stabilizes the disulfide bonds.

Original languageEnglish (US)
Pages (from-to)1718-1729
Number of pages12
JournalProtein Science
Volume4
Issue number9
StatePublished - 1995

Fingerprint

Enterotoxins
Circular Dichroism
Escherichia coli
Magnetic Resonance Spectroscopy
Hot Temperature
Nuclear magnetic resonance
Disulfides
Enterotoxigenic Escherichia coli
Bioactivity
Simulated annealing
Oxidation-Reduction
Toxicity
Conformations
Urea
Diarrhea
Buffers
Animals
Amino Acids
Peptides
Geometry

Keywords

  • distance geometry
  • enterotoxin
  • NMR spectroscopy
  • secretory diarrhea

ASJC Scopus subject areas

  • Biochemistry

Cite this

Sukumar, M., Rizo-Rey, J., Wall, M., Dreyfus, L. A., Kupersztoch, Y. M., & Gierasch, L. M. (1995). The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism. Protein Science, 4(9), 1718-1729.

The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism. / Sukumar, M.; Rizo-Rey, Jose; Wall, M.; Dreyfus, L. A.; Kupersztoch, Y. M.; Gierasch, L. M.

In: Protein Science, Vol. 4, No. 9, 1995, p. 1718-1729.

Research output: Contribution to journalArticle

Sukumar, M, Rizo-Rey, J, Wall, M, Dreyfus, LA, Kupersztoch, YM & Gierasch, LM 1995, 'The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism', Protein Science, vol. 4, no. 9, pp. 1718-1729.
Sukumar, M. ; Rizo-Rey, Jose ; Wall, M. ; Dreyfus, L. A. ; Kupersztoch, Y. M. ; Gierasch, L. M. / The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism. In: Protein Science. 1995 ; Vol. 4, No. 9. pp. 1718-1729.
@article{7c55329a669946e6990966d4ce7452e8,
title = "The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism",
abstract = "The heat-stable enterotoxin b (STb) is secreted by enterotoxigenic Escherichia coli that cause secretory diarrhea in animals and humans. It is a 48-amino acid peptide containing two disulfide bridges, between residues 10 and 48 and 21 and 36, which are crucial for its biological activity. Here, we report the solution structure of STb determined by two- and three-dimensional NMR methods. Approximate interproton distances derived from NOE data were used to construct structures of STb using distance-geometry and simulated annealing procedures. The NMR-derived structure shows that STb is helical between residues 10 and 22 and residues 38 and 44. The helical structure in the region 10-22 is amphipathic and exposes several polar residues to the solvent, some of which have been shown to be important in determining the toxicity of STb. The hydrophobic residues on the opposite face of this helix make contacts with the hydrophobic residues of the C-terminal helix. The loop region between residues 21 and 36 has another cluster of hydrophobic residues and exposes Arg 29 and Asp 30, which have been shown to be important for intestinal secretory activity. CD studies show that reduction of disulfide bridges results in a dramatic loss of structure, which correlates with loss of function. Reduced STb adopts a predominantly random-coil conformation. Chromatographic measurements of concentrations of native, fully reduced, and single disulfide species in equilibrium mixture of STb in redox buffers indicate that the formation of the two disulfide bonds in STb is only moderately cooperative. Similar measurements in the presence of 8 M urea suggest that the native secondary structure significantly stabilizes the disulfide bonds.",
keywords = "distance geometry, enterotoxin, NMR spectroscopy, secretory diarrhea",
author = "M. Sukumar and Jose Rizo-Rey and M. Wall and Dreyfus, {L. A.} and Kupersztoch, {Y. M.} and Gierasch, {L. M.}",
year = "1995",
language = "English (US)",
volume = "4",
pages = "1718--1729",
journal = "Protein Science",
issn = "0961-8368",
publisher = "Cold Spring Harbor Laboratory Press",
number = "9",

}

TY - JOUR

T1 - The structure of Escherichia coli heat-stable enterotoxin b by nuclear magnetic resonance and circular dichroism

AU - Sukumar, M.

AU - Rizo-Rey, Jose

AU - Wall, M.

AU - Dreyfus, L. A.

AU - Kupersztoch, Y. M.

AU - Gierasch, L. M.

PY - 1995

Y1 - 1995

N2 - The heat-stable enterotoxin b (STb) is secreted by enterotoxigenic Escherichia coli that cause secretory diarrhea in animals and humans. It is a 48-amino acid peptide containing two disulfide bridges, between residues 10 and 48 and 21 and 36, which are crucial for its biological activity. Here, we report the solution structure of STb determined by two- and three-dimensional NMR methods. Approximate interproton distances derived from NOE data were used to construct structures of STb using distance-geometry and simulated annealing procedures. The NMR-derived structure shows that STb is helical between residues 10 and 22 and residues 38 and 44. The helical structure in the region 10-22 is amphipathic and exposes several polar residues to the solvent, some of which have been shown to be important in determining the toxicity of STb. The hydrophobic residues on the opposite face of this helix make contacts with the hydrophobic residues of the C-terminal helix. The loop region between residues 21 and 36 has another cluster of hydrophobic residues and exposes Arg 29 and Asp 30, which have been shown to be important for intestinal secretory activity. CD studies show that reduction of disulfide bridges results in a dramatic loss of structure, which correlates with loss of function. Reduced STb adopts a predominantly random-coil conformation. Chromatographic measurements of concentrations of native, fully reduced, and single disulfide species in equilibrium mixture of STb in redox buffers indicate that the formation of the two disulfide bonds in STb is only moderately cooperative. Similar measurements in the presence of 8 M urea suggest that the native secondary structure significantly stabilizes the disulfide bonds.

AB - The heat-stable enterotoxin b (STb) is secreted by enterotoxigenic Escherichia coli that cause secretory diarrhea in animals and humans. It is a 48-amino acid peptide containing two disulfide bridges, between residues 10 and 48 and 21 and 36, which are crucial for its biological activity. Here, we report the solution structure of STb determined by two- and three-dimensional NMR methods. Approximate interproton distances derived from NOE data were used to construct structures of STb using distance-geometry and simulated annealing procedures. The NMR-derived structure shows that STb is helical between residues 10 and 22 and residues 38 and 44. The helical structure in the region 10-22 is amphipathic and exposes several polar residues to the solvent, some of which have been shown to be important in determining the toxicity of STb. The hydrophobic residues on the opposite face of this helix make contacts with the hydrophobic residues of the C-terminal helix. The loop region between residues 21 and 36 has another cluster of hydrophobic residues and exposes Arg 29 and Asp 30, which have been shown to be important for intestinal secretory activity. CD studies show that reduction of disulfide bridges results in a dramatic loss of structure, which correlates with loss of function. Reduced STb adopts a predominantly random-coil conformation. Chromatographic measurements of concentrations of native, fully reduced, and single disulfide species in equilibrium mixture of STb in redox buffers indicate that the formation of the two disulfide bonds in STb is only moderately cooperative. Similar measurements in the presence of 8 M urea suggest that the native secondary structure significantly stabilizes the disulfide bonds.

KW - distance geometry

KW - enterotoxin

KW - NMR spectroscopy

KW - secretory diarrhea

UR - http://www.scopus.com/inward/record.url?scp=0029153602&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029153602&partnerID=8YFLogxK

M3 - Article

C2 - 8528070

AN - SCOPUS:0029153602

VL - 4

SP - 1718

EP - 1729

JO - Protein Science

JF - Protein Science

SN - 0961-8368

IS - 9

ER -