Advanced

Role of Aromatic Side Chains in the Binding of Volatile General Anesthetics to a Four-alpha-helix Bundle.

Manderson, Gavin LU and Johansson, Jonas S (2002) In Biochemistry 41(12). p.4080-4087
Abstract
Currently, the mechanism by which anesthesia occurs is thought to involve the direct binding of inhaled anesthetics to ligand-gated ion channels. This hypothesis is being studied using four--helix bundles as model systems for the transmembrane domains of the natural "receptor" proteins. This study concerns the role in anesthetic binding played by aromatic side chains in the binding cavity of a four--helix bundle designed to assume a Rop-like fold. Specifically, the effect of the substitution W15Y on bundle structure, stability, and anesthetic binding energetics was investigated. No appreciable effect of substituting W for Y on the secondary structure or the thermodynamic stability of the four--helix bundle was identified. However, the... (More)
Currently, the mechanism by which anesthesia occurs is thought to involve the direct binding of inhaled anesthetics to ligand-gated ion channels. This hypothesis is being studied using four--helix bundles as model systems for the transmembrane domains of the natural "receptor" proteins. This study concerns the role in anesthetic binding played by aromatic side chains in the binding cavity of a four--helix bundle designed to assume a Rop-like fold. Specifically, the effect of the substitution W15Y on bundle structure, stability, and anesthetic binding energetics was investigated. No appreciable effect of substituting W for Y on the secondary structure or the thermodynamic stability of the four--helix bundle was identified. However, the substitution W15Y resulted in about 6- and 3-fold decreases in halothane and chloroform binding affinities, respectively. This effect may reflect weaker dipole-aromatic quadrupole interactions between the aromatic side chain and the anesthetic in the tyrosine-containing species, which possesses the smaller aromatic ring system. For these anesthetic binding proteins, this class of interaction occurs when the permanent nonspherical distribution of electrons in the aromatic ring systems interact with the weakly acidic CH group of the anesthetics. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
in
Biochemistry
volume
41
issue
12
pages
4080 - 4087
publisher
The American Chemical Society
external identifiers
  • scopus:0037177228
ISSN
0006-2960
DOI
10.1021/bi0160718
language
English
LU publication?
no
id
4efe4094-8b3c-4da2-a3db-1d4d1d94ebb8 (old id 1125015)
date added to LUP
2008-05-27 12:40:05
date last changed
2017-01-01 05:10:13
@article{4efe4094-8b3c-4da2-a3db-1d4d1d94ebb8,
  abstract     = {Currently, the mechanism by which anesthesia occurs is thought to involve the direct binding of inhaled anesthetics to ligand-gated ion channels. This hypothesis is being studied using four--helix bundles as model systems for the transmembrane domains of the natural "receptor" proteins. This study concerns the role in anesthetic binding played by aromatic side chains in the binding cavity of a four--helix bundle designed to assume a Rop-like fold. Specifically, the effect of the substitution W15Y on bundle structure, stability, and anesthetic binding energetics was investigated. No appreciable effect of substituting W for Y on the secondary structure or the thermodynamic stability of the four--helix bundle was identified. However, the substitution W15Y resulted in about 6- and 3-fold decreases in halothane and chloroform binding affinities, respectively. This effect may reflect weaker dipole-aromatic quadrupole interactions between the aromatic side chain and the anesthetic in the tyrosine-containing species, which possesses the smaller aromatic ring system. For these anesthetic binding proteins, this class of interaction occurs when the permanent nonspherical distribution of electrons in the aromatic ring systems interact with the weakly acidic CH group of the anesthetics.},
  author       = {Manderson, Gavin and Johansson, Jonas S},
  issn         = {0006-2960},
  language     = {eng},
  number       = {12},
  pages        = {4080--4087},
  publisher    = {The American Chemical Society},
  series       = {Biochemistry},
  title        = {Role of Aromatic Side Chains in the Binding of Volatile General Anesthetics to a Four-alpha-helix Bundle.},
  url          = {http://dx.doi.org/10.1021/bi0160718},
  volume       = {41},
  year         = {2002},
}