Percoll reversibly inhibits superoxide dismutase

Abstract

Incubation of pea leaf extracts (Pisum sativum L.) at 6 degrees C in isoosmotic media containing different Percoll concentrations significantly represses the total superoxide dismutase (SOD) activity in a concentration- and time-dependent manner.After 24 h incubation at 6 degrees C, 30-45% Percoll concentrations bring about an inhibition of Mn-SOD activity of more than 50%.Isozyme Cu,Zn-SOD II is affected to a lesser extent, with a maximum inhibition of 36% at high Percoll concentrations, whereas isozyme Cu,Zn-SOD I undergoes only slight variations.However, dilution of the samples followed by electrophoresis completely removes the Percoll inhibitory action.Results suggest that superoxide dismutases could be adsorbed onto the Percoll surface through electrostatic interactions.