In vitro screening for inhibitor of cloned Drosophila melanogaster tyramine-β-hydroxylase and docking studies.

Biogenic amines are common biologically active substances extended within the whole animal kingdom where they play vital roles as signal transducer as well as regulator of cell functions. One of these biogenic amines called octopamine (OA) is synthesized from tyramine (TA) by the catalysis of tyramineS-hydroxylase (T beta H) originated in the insect nervous system. Both TA and OA act as neurotransmitters, neurohormones and neuromodulators in the arthropod nervous system. Herein, the inhibitory activity of 1-arylimidazole-2(3H)-thiones (AITs) was tested on cloned Drosophila tyramine-beta-hydroxylase (DmT beta H) expressed in Bombyx mori strain. Radiolabelled 3H-TA was used to analyze the activity of AITs exhibited inhibitory effects on DmT beta H, whose ID50 values range from 0.02 to 2511 nM where DmTSH was inhibited in a dose-dependent manner at pH 7.6 and 25 degrees C during a 30 min of incubation. To understand the catalytic role of the TSH, a three dimensional structure of the TSH from Drosophila melanogaster was constructed by homology modeling using the Phyre2 web server with 100% confidence. The modeled three-dimensional structure of TSH was used to perform the docking study with AITs. This may give more insights to precise design of inhibitors for TSH to control insect's population. (C) 2016 Elsevier B.V. All rights reserved.