PECULIARITIES OF SALICYLIC ACID AND ASPIRIN BINDING TO ACID-SENSITIVE ION CHANNELS OF TRICHOPLAX ADHAERENS

Abstract

Acid-sensitive ion channels (ASICs) represent a family of membrane three subunits' DEG/ENaC proteins that transport Na+ ions and are found in representatives of many taxonomic groups [1]. DEG/EnaC channels include such structural domains as the palm, β-ball, knuckle, finger, thumb and wrist [2]. They are involved in many physiological processes as proton-regulated channels, when the pH of the extracellular environment changes [3]. DEG/ENaC channels are associated with a wide range of cellular functions, such as pain sensation and epithelial Na+ transport [4]. These channels have different gating properties, from almost constant opening to rapid inactivation, so numerous pathologies are associated with damage to these channels [5]. Traditionally, the functions of these channels have been studied using toxins [6]. We found 9 acid-sensitive ion channel genes and 12 homologs with unknown function in the Trichoplax adhaerens genome, of which two amino acid sequences (QEP99390.1 and XP_002115321.1) were folded into 3D-models and used to dock amiloride, aspirin and salicylic acid. Salicylates have multiple binding sites on the acid-sensitive trichoplax receptors, including the acid pocket that is a proton sensor, which suggests their possible application in modulating the activity of the ASIC-channels of T. adhaerens.