NDLI: Continuum solvent model calculations of alamethicin-membrane interactions: thermodynamic aspects.

Content Provider	PubMed Central
Author	Kessel, A. Cafiso, D. S. Ben-tal, N.
Abstract	Alamethicin is a 20-amino acid antibiotic peptide that forms voltage-gated ion channels in lipid bilayers. Here we report calculations of its association free energy with membranes. The calculations take into account the various free-energy terms that contribute to the transfer of the peptide from the aqueous phase into bilayers of different widths. The electrostatic and nonpolar contributions to the solvation free energy are calculated using continuum solvent models. The contributions from the lipid perturbation and membrane deformation effects and the entropy loss associated with peptide immobilization in the bilayer are estimated from a statistical thermodynamic model. The calculations were carried out using two classes of experimentally observed conformations, both of which are helical: the NMR and the x-ray crystal structures. Our calculations show that alamethicin is unlikely to partition into bilayers in any of the NMR conformations because they have uncompensated backbone hydrogen bonds and their association with the membrane involves a large electrostatic solvation free energy penalty. In contrast, the x-ray conformations provide enough backbone hydrogen bonds for the peptide to associate with bilayers. We tested numerous transmembrane and surface orientations of the peptide in bilayers, and our calculations indicate that the most favorable orientation is transmembrane, where the peptide protrudes approximately 4 A into the water-membrane interface, in very good agreement with electron paramagnetic resonance and oriented circular dichroism measurements. The calculations were carried out using two alamethicin isoforms: one with glutamine and the other with glutamate in the 18th position. The calculations indicate that the two isoforms have similar membrane orientations and that their insertion into the membrane is likely to involve a 2-A deformation of the bilayer, again, in good agreement with experimental data. The implications of the results for the biological function of alamethicin and its capacity to oligomerize and form ion channels are discussed.
Related Links	http://dx.doi.org/10.1016/s0006-3495(00)76617-3
Ending Page	583
Page Count	13
Starting Page	571
File Format	PDF
ISSN	00063495
e-ISSN	15420086
Journal	Biophysical Journal
Issue Number	2
Volume Number	78
Language	English
Publisher Date	2000-02-01
Access Restriction	Open
Subject Keyword	Biophysics Research in Higher Education
Content Type	Text
Resource Type	Article
Subject	Biophysics

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Implicit solvent model estimates of the stability of model structures of the alamethicin channel

Lipid-alamethicin interactions influence alamethicin orientation

Continuum solvent model studies of the interactions of an anticonvulsant drug with a lipid bilayer.

Solvent-Solute Interactions within the Nexal Membrane

Interactions of the M2δ Segment of the Acetylcholine Receptor with Lipid Bilayers: A Continuum-Solvent Model Study

Simulation Studies of Alamethicin-Bilayer Interactions

Transduction of membrane tension by the ion channel alamethicin.

A thermodynamic approach to Alamethicin pore formation

Dynamics of Membrane Tethers Reveal Novel Aspects of Cytoskeleton-Membrane Interactions in Axons

Continuum solvent model calculations of alamethicin-membrane interactions: thermodynamic aspects.

Similar Documents

Implicit solvent model estimates of the stability of model structures of the alamethicin channel

Lipid-alamethicin interactions influence alamethicin orientation

Continuum solvent model studies of the interactions of an anticonvulsant drug with a lipid bilayer.

Solvent-Solute Interactions within the Nexal Membrane

Interactions of the M2δ Segment of the Acetylcholine Receptor with Lipid Bilayers: A Continuum-Solvent Model Study

Simulation Studies of Alamethicin-Bilayer Interactions

Transduction of membrane tension by the ion channel alamethicin.

A thermodynamic approach to Alamethicin pore formation

Dynamics of Membrane Tethers Reveal Novel Aspects of Cytoskeleton-Membrane Interactions in Axons

Continuum solvent model calculations of alamethicin-membrane interactions: thermodynamic aspects.