On the possible mode of action of neurohormones on cholinesterase activity in the ventral nerve cord of scorpion, Heterometrus fulvipes.

It is shown that Km of ChE is not affected by the neurohormones but Vmax is increased and decreased in presence of acceleratory and inhibitory neurohormones respectively. Hence it is suggested that the neurohormones might modulate the enzyme activity be altering the maximal velocities (Vmax) rather than affecting the enzyme affinity (Km) towards the substrate.