| Autor: |
Shchagina LV, Grinfel'dt AE, Lev AA |
| Jazyk: |
ruština |
| Zdroj: |
Biofizika [Biofizika] 1980 Jul-Aug; Vol. 25 (4), pp. 648-53. |
| Abstrakt: |
Simultaneous studies were carried out of isotope and electric parameters of spheric bilayer membranes modified with gramicidin A and its analog O-pyromellithylgramicidin (PG) having three negative charges on the N-end of the molecule. The relationship between the electric coefficients of permeability and the isotope ones PG/P* = n was determined by two independent methods. It has been found that for the membranes modified with gramicidin A in RbCl concentrations from 2.2 x 10(-3) to 10(-1) M the value n is constant and approximates 2 and with RbCl concentration 1 M, n = 1.6. For the membranes modified with PG in 0.1 M solutions of PbCl n = 2. The results obtained in terms of the model of unilinear ion diffusion in a narrow pore indicate that in a gramicidin channel there are two sites of cation binding which are located near the channel mouth. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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