Inhibition by aconitine of aconitase of pig heart

The present paper describes the in vitro inhibition type, inhibition constant and inhibition rate of pig heart aconitase by aconitine. The inhibition of aconitase activity by aconitine is totally non-competitive. The datum of inhibition constant, Ki = 0.11 +/- 0.01 mmol/l, indicates high affinity of aconitine by aconitase. The rate constant of inhibition kl = 49 min-1, the half-life for aconitase inhibition of 1 min and the 50% inhibition time of 8 min by 0.1 mmol/l aconitine show high specific inhibition of the enzyme by the inhibitor. These results suggest a possible molecular reason for the toxic and pharmacological actions produced on experimental animals by aconitine.