ρ-Nitrophenylacetate hydrolysis by honey bee esterases: kinetics and inhibition

Abstract

1. The kinetics and inhibition of ρ-nitrophenylacetate hydrolysis by cytosolic esterases of 1-day old female honey bees, Apis mellifera L., were studied.

2. The calculated values obtained were K_m = 2.27x 10⁻⁵M and V_max = 2.48 × 10⁻⁸mol/s per mg protein.

3. The inhibition mechanisms examined for four organophosphorus insecticides were highly competitive in nature and based on competitive inhibition coefficients the order of toxicity was naled >dichlorvos>cis-mevinphos = trans-mevinphos.

4. Comparisons are made with the alfalfa leafcutting bee, Megachile rotundata (Fab).