Inhibition of na/h antiport activity in sugar beet tonoplast by analogs of amiloride.
The effects of amiloride and a series of amiloride analogs have been tested on the Na(+)/H(+) antiport activity in intact vacuoles and tonoplast vesicles isolated from sugar beet cell suspension cultures. There is a competitive interaction between amiloride analogs and sodium. Substitution of one or both H-atoms of the 5-amino group of amiloride (apparent K(i) about 150 micromolar) resulted in a 3- to 200-fold increase in inhibitory potency of the antiport activity.
Blumwald
E
E
Department of Botany, University of Toronto, Toronto, Ontario, Canada M5S 1A1.
Cragoe
E J
EJ
Poole
R J
RJ