Advanced

Binding of the volatile general anesthetics halothane and isoflurane to a mammalian beta-barrel protein.

Johansson, J.S.; Manderson, Gavin LU ; Ramoni, R.; Grolli, S and Eckenhoff, R.G. (2005) In The FEBS Journal 272(2). p.573-581
Abstract
A molecular understanding of volatile anesthetic mechanisms of action will require structural descriptions of anesthetic–protein complexes. Porcine odorant binding protein is a 157 residue member of the lipocalin family that features a large β-barrel internal cavity (515 ± 30 Å3) lined predominantly by aromatic and aliphatic residues. Halothane binding to the β-barrel cavity was determined using fluorescence quenching of Trp16, and a competitive binding assay with 1-aminoanthracene. In addition, the binding of halothane and isoflurane were characterized thermodynamically using isothermal titration calorimetry. Hydrogen exchange was used to evaluate the effects of bound halothane and isoflurane on global protein dynamics. Halothane bound to... (More)
A molecular understanding of volatile anesthetic mechanisms of action will require structural descriptions of anesthetic–protein complexes. Porcine odorant binding protein is a 157 residue member of the lipocalin family that features a large β-barrel internal cavity (515 ± 30 Å3) lined predominantly by aromatic and aliphatic residues. Halothane binding to the β-barrel cavity was determined using fluorescence quenching of Trp16, and a competitive binding assay with 1-aminoanthracene. In addition, the binding of halothane and isoflurane were characterized thermodynamically using isothermal titration calorimetry. Hydrogen exchange was used to evaluate the effects of bound halothane and isoflurane on global protein dynamics. Halothane bound to the cavity in the β-barrel of porcine odorant binding protein with dissociation constants of 0.46 ± 0.10 mm and 0.43 ± 0.12 mm determined using fluorescence quenching and competitive binding with 1-aminoanthracene, respectively. Isothermal titration calorimetry revealed that halothane and isoflurane bound with Kd values of 80 ± 10 µm and 100 ± 10 µm, respectively. Halothane and isoflurane binding resulted in an overall stabilization of the folded conformation of the protein by −0.9 ± 0.1 kcal·mol−1. In addition to indicating specific binding to the native protein conformation, such stabilization may represent a fundamental mechanism whereby anesthetics reversibly alter protein function. Because porcine odorant binding protein has been successfully analyzed by X-ray diffraction to 2.25 Å resolution [1], this represents an attractive system for atomic-level structural studies in the presence of bound anesthetic. Such studies will provide much needed insight into how volatile anesthetics interact with biological macromolecules. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
porcine odorant binding protein, isothermal titration calorimetry, isoflurane, anesthetic–protein interaction, halothane
in
The FEBS Journal
volume
272
issue
2
pages
573 - 581
publisher
Federation of European Neuroscience Societies and Blackwell Publishing Ltd
external identifiers
  • scopus:12544255915
ISSN
1742-464X
DOI
10.1111/j.1742-4658.2004.04500.x
language
English
LU publication?
yes
id
f09ff641-6947-4ab0-9d12-c2fa5c1a06e7 (old id 1133799)
date added to LUP
2008-06-17 12:48:33
date last changed
2017-01-01 06:52:00
@article{f09ff641-6947-4ab0-9d12-c2fa5c1a06e7,
  abstract     = {A molecular understanding of volatile anesthetic mechanisms of action will require structural descriptions of anesthetic–protein complexes. Porcine odorant binding protein is a 157 residue member of the lipocalin family that features a large β-barrel internal cavity (515 ± 30 Å3) lined predominantly by aromatic and aliphatic residues. Halothane binding to the β-barrel cavity was determined using fluorescence quenching of Trp16, and a competitive binding assay with 1-aminoanthracene. In addition, the binding of halothane and isoflurane were characterized thermodynamically using isothermal titration calorimetry. Hydrogen exchange was used to evaluate the effects of bound halothane and isoflurane on global protein dynamics. Halothane bound to the cavity in the β-barrel of porcine odorant binding protein with dissociation constants of 0.46 ± 0.10 mm and 0.43 ± 0.12 mm determined using fluorescence quenching and competitive binding with 1-aminoanthracene, respectively. Isothermal titration calorimetry revealed that halothane and isoflurane bound with Kd values of 80 ± 10 µm and 100 ± 10 µm, respectively. Halothane and isoflurane binding resulted in an overall stabilization of the folded conformation of the protein by −0.9 ± 0.1 kcal·mol−1. In addition to indicating specific binding to the native protein conformation, such stabilization may represent a fundamental mechanism whereby anesthetics reversibly alter protein function. Because porcine odorant binding protein has been successfully analyzed by X-ray diffraction to 2.25 Å resolution [1], this represents an attractive system for atomic-level structural studies in the presence of bound anesthetic. Such studies will provide much needed insight into how volatile anesthetics interact with biological macromolecules.},
  author       = {Johansson, J.S. and Manderson, Gavin and Ramoni, R. and Grolli, S and Eckenhoff, R.G.},
  issn         = {1742-464X},
  keyword      = {porcine odorant binding protein,isothermal titration calorimetry,isoflurane,anesthetic–protein interaction,halothane},
  language     = {eng},
  number       = {2},
  pages        = {573--581},
  publisher    = {Federation of European Neuroscience Societies and Blackwell Publishing Ltd},
  series       = {The FEBS Journal},
  title        = {Binding of the volatile general anesthetics halothane and isoflurane to a mammalian beta-barrel protein.},
  url          = {http://dx.doi.org/10.1111/j.1742-4658.2004.04500.x},
  volume       = {272},
  year         = {2005},
}