Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Amine spin probe permeability in sonicated liposomes.

A P Todd1, R J Mehlhorn, R I Macey

  • 1Department of Physiology-Anatomy, University of California, Berkeley 94720.

The Journal of Membrane Biology
|July 1, 1989
PubMed
Summary

Electron paramagnetic resonance (EPR) measured amine nitroxide spin probe permeabilities in liposomes. The rate-limiting step for nonelectrolyte permeation is not at the membrane interface but within the bilayer

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Increased vulnerability of human erythrocytes to hydroperoxide damage after exposure to cigarette smoke or 1-chloro-2,4-dinitrobenzene in vitro.

Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco·2000
Same author

Osmotic equilibrium and elastic properties of eel intestinal vesicles.

The Journal of membrane biology·1999
Same author

Kinetics of water transport in eel intestinal vesicles.

The Journal of membrane biology·1999
Same author

Loss of glutathione, ascorbate recycling, and free radical scavenging in human erythrocytes exposed to filtered cigarette smoke.

Archives of biochemistry and biophysics·1998
Same author

Mechanical properties of brush border membrane vesicles from kidney proximal tubule.

The Journal of membrane biology·1997
Same author

Water permeability of brush border membrane vesicles from kidney proximal tubule.

The Journal of membrane biology·1997

Area of Science:

  • Biophysics
  • Membrane Biophysics
  • Physical Chemistry

Background:

  • Understanding nonelectrolyte permeation through lipid bilayers is crucial for drug delivery and membrane transport.
  • Amine nitroxide spin probes offer a unique tool to study membrane dynamics and permeability.
  • Previous models for nonelectrolyte permeation have limitations in explaining experimental observations.

Purpose of the Study:

  • To investigate the rate-limiting steps and selectivity factors governing the permeation of amine nitroxide spin probes across liposomes.
  • To evaluate the applicability of existing models, such as free volume and hydrocarbon sheet models, to nonelectrolyte permeation.
  • To elucidate the specific region within the lipid bilayer that controls the rate of probe permeation.

Main Methods:

  • Measurement of permeation rates using electron paramagnetic resonance (EPR) spectroscopy.
  • Utilizing liposomes with varying lipid compositions, including phosphatidylcholine, phosphatidic acid, and cholesterol.
  • Analysis of probe selectivity patterns in liposomes and red blood cells.

Main Results:

  • Permeation rate-limiting step is not adsorption/desorption at the aqueous/membrane interface for several probe-liposome combinations.
  • Liposomes do not exhibit selectivity against probes based on molecular volume, contradicting the free volume model.
  • Probe permeabilities are lower than predicted by the hydrocarbon sheet model, indicating a more polar rate-limiting region.

Conclusions:

  • The rate-limiting region for nonelectrolyte permeation is not the center of the bilayer but the ordered acyl chain segments near the glycerol backbone.
  • Existing free volume and hydrocarbon sheet models are insufficient to explain the observed permeation behavior of these probes.
  • The findings suggest a more complex picture of membrane permeation, influenced by the specific microenvironment within the lipid bilayer.

Related Experiment Videos