IN SILICO MODELING OF THE INTERACTION OF NBD STEROIDS WITH INSECT STEROID-BINDING PROTEIN SPC-2

Insects are unable to synthesize cholesterol de novo from acetyl-CoA, but most of them require it as a component of cell membranes and a precursor for the synthesis of the hormone ecdysone. In the case of herbivorous insects, a three-step oxidative removal of the 24-ethyl group of beta-sitosterol is carried out to convert it to 24-dehydrocholesterol and then to cholesterol. It is important to note that in the biosynthesis of ecdysone, the oxidation of cholesterol is carried out by Neverlend Reiske monooxygenase and little-studied “black box” enzymes. Intracellular transport of cholesterol and other steroids in insects is also important for survival, as illustrated by the steroid transfer protein SCP-2. Since fluorescent 3beta-hydroxy-5-ene steroids are used to study the distribution and metabolism of cholesterol, and in the literature, as far as we know, such studies were carried out only for a pair of SCP-2 with commercial 22-NBD-cholesterol, we performed calculations in silico for obtained 7-nitrobenzoxadiazole (NBD) derivatives codenamed DAM-NBD ​​and NBD-pip-CCF.

Synthesis of NBD-pip-CCF was carried out by conjugation of cholesteryl chloroformate (CCF) and 4-Chloro-7-nitrobenzofurazan through a piperazine (Pip) fragment. To obtain DAM-NBD, dehydroepiandrosterone was converted to 17-methylamino derivative (DAM), after which it was subjected to acid treatment, neutralization and NBD-ylation. Biological properties were predicted in silico using Autodock Vina and FYTdock.

The results of computer simulation showed the possibility of binding synthetic DAM-NBD and CCFNBDpip. The data obtained open up prospects for the use of the obtained substances in vitro to search for mechanisms to control the viability of insects.