Preliminary characterization of an anion stimulated atpase from pisum sativum cultivar alaska plasma membrane
Hendrix, D.L.; Pierce, W.S.
Plant Science Letters 18(4): 365-374
An ATPase isolated from Pisum epicotyl which had previously been shown to be associated with plasma membrane was characterized with respect to substrate specificity, pH optima and ion stimulation. The enzyme exhibits a decided preference for ATP as a substrate and prefers slightly acidic pH values. It is activated by Mg2+ or Mn2+ but, unlike most other higher plant plasma membrane isolates, it is stimulated by monovalent anions rather than monovalent cations. It exhibits an unusual inhibition by nitrate at high pH values.