The docking by AutoDock Vina program. Top 300

common herbivore, H. armigera, which
has become resistant to traditional insecticides, feeds on more than 100
species of crops. The need is to look for more advanced insecticides with
greater efficacy to get desired result. For the development and survival of
cotton bollworm the SCP-2, a sterol carrier protein appears to be an absolutely
necessary gene. It is verified by Expression knockdown experiments of HaSCP-x/2
transcripts that it could delay both larval development and decrease fertility.
This study was conducted to investigate the interaction mechanism and to
illustrate the binding model for the active site of HaSCP-2 with its potential
inhibitors. Larval rearing was carried out under optimal rearing conditions. The
three-dimensional structure of SCP-2 for virtual screening was retrieved from
Protein Data Bank structure was preprocessed and converted into PDBQT file
format. For virtual screening study natural product library & Mybridge
library were used a total of 218,780 compounds were selected for molecular
docking by AutoDock Vina program. Top 300 highest ranked compounds were selected
for further screening. On the basis of structural diversity and docking scores nine
compounds were selected as potential candidates for bioassay. Larvae were
treated with selected nine compounds with control group. In vivo bioassays
results for H1 and H14 showed these two compounds had exerted different degrees
of inhibitory activity to growth of the H.
armigera. Doses of H1 or H14
given at the ontogenic stage delayed the larval development. It is suspected
that the high levels of HaSCP-2 inhibitors induced the expression of
detoxification enzymes, such as P450 or GST. According to molecular docking H1
and H14 were bound to the active pocket of HaSCP-2 in a similar mode, and each
made contact with the helix a2 and the helix a5 via hydrophobic interactions
and van der Waals interactions. Furthermore, bioassay was adopted to verify the
virtual screening results, and the results indicated that H1 andH14 are vital
useful lead compounds for further optimization and designing of novel
SCP-2-specific pesticides.