Photochemical Observation of Ion Flows in Membrane Channels

Abstract

Laser Doppler velocimetry and photochemical observation of T(l) (I) ion flows are used to characterize the permeation properties of ions within gramicidin channels. The laser Doppler velocimetry provides a direct experimental determination of the distribution of ion velocities within these channels. For this information, it becomes possible to deduce the mechanism for ion transport, e.g. transport via discrete sites or continuum diffusion. The photochemical studies permit an experimental determination of the fraction of the total current carried by the T(l) (I) ion in mixed cation systems using a dye molecule whose fluorescence is quenched by the permeating T(l) (I) ion. This ion differentiation technique is utilized for a detailed study of T(l) (I) ion in the gramicidin channel. This ion is a permeant ion at large mole fractions but becomes a channel blocker at small T(l) (I) ion mole fractions. Keywords: Membranes, Vesicles, Lipid bilayers, Models, Latex spheres.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1989
Accession Number
ADA212449

Entities

People

  • Michael E. Starzak

Organizations

  • Binghamton University

Tags

DTIC Thesaurus Topics

  • Chemical Compounds
  • Chemistry
  • Classification
  • Contracts
  • Detection
  • Doppler Effect
  • Doppler Systems
  • Electrodes
  • Flow
  • Fluorescence
  • Frequency
  • Frequency Domain
  • Gel Electrophoresis
  • High Resolution
  • Lasers
  • Scattering
  • Security

Fields of Study

  • Physics

Readers

  • Cellular and Molecular Pathways of Apoptosis.
  • Electrochemical Engineering/ Fuel Cell Technologies
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy