Obtention of natural membranes enriched with GABAA receptor from disease vector insects (Aedes aegypti and Triatoma infestans)

FELSZTYNA, I; COLMANO, GN; TURINA A; SÁNCHEZ M; MIGUEL V; GARCÍA D

Buenos Aires

Congreso; Reunión conjunta de Sociedades de Biociencias.; 2017

γ-aminobuyric acid (GABA) is the major inhibitory neurotransmitter in the vertebrate CNS. Its specific receptor, the GABAA receptor (GABAA-R), is constituted by five subunits which compose a chloride channel. In mammalian organisms there is a wide diversity of receptor subunits, while in insects this variety is considerably minor, being the so-called RDL the most representative subunit. Considering that the receptor subunit composition is critical for the pharmacological and biophysical properties of GABAA-Rs, functional and structural differences between receptors from mammals and insects provide multiple opportunities for the design of more selective and non-toxic insecticides. Considering this argument, in the present work we obtained insect natural membranes as a source of GABAA-Rs to be used in the search of new insecticide agents. The membranes were extracted from the head-thorax portion of A. aegypti larvae (IV stage) or T. infestans nymphs (V stage), by differential centrifugation procedures. Protein electrophoretic profiles contained in the purified membranes showed bands with MW similar to those described for GABAA-Rs from other insects. In addition, we also determined the presence of GABAA-Rs in the samples by using radiolabeled ligands which recognize specific sites in the receptor. All these results indicate that, through the procedures used in the work, it is possible to obtain natural membranes enriched in native GABAA-Rs from insects, which could be utilized for the evaluation of compounds able to block the receptor channel, with a consequent potential insecticidal activity.