Measurements and implications of the membrane dipole potential.
Annu Rev Biochem
; 81: 615-35, 2012.
Article
en En
| MEDLINE
| ID: mdl-22443933
ABSTRACT
There are three kinds of membrane potentials the surface potentials, resulting from the accumulation of charges at the membrane surfaces; the transmembrane potential, determined by imbalance of charge in the aqueous solutions; and the dipole potential, a membrane-internal potential from the dipolar components of the phospholipids and interface water. The absolute value of the dipole potential has been very difficult to measure, although its value has been estimated to be in the range of 200-1,000 mV from ion translocation rates (determined by the planar lipid bilayer method), the surface potential of lipid monolayers (determined by the lipid monolayer method), molecular-dynamics calculations, and electron scattering using cryoelectron microscopy (cryo-EM). Spectroscopy methods have also been used to monitor the dipole potential changes on the basis of the observed fluorescence changes of voltage-sensitive probes. The dipole potential accounts for the much larger permeability of a bare phospholipid membrane to anions than cations and affects the conformation and function of membrane proteins.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Bioquímica
/
Membrana Celular
/
Potenciales de la Membrana
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Annu Rev Biochem
Año:
2012
Tipo del documento:
Article
País de afiliación:
Estados Unidos