New approaches for the identification of KChIP2 ligands to study the KV4.3 channelosome in atrial fibrillati

Abstract

Ion channels are macromolecular complexes present in the plasma membrane and in intracellular organelles of the cells, where they play important functions. The dysfunction of these channels results in several disorders named channelopathies, which represent a challenge for study and treatment.[1] We are focused on voltage-gated potassium channels, specifically on KV4.3. Kv4.3 is expressed in smooth muscle, heart and brain. Within the heart, Kv4.3 channels generate the transient outward potassium current (ITO). However, ITO characteristics are only observed when Kv4.3 assemble with accessory subunits as KChIP2 and DPP6. KV4.3 channelosome play a key role in atrial fibrillation (AF),the most common cardiac arrhythmia, with an estimated prevalence in the general population of 1.5–2%. However, current antiarrhythmic drugs for AF prevention have limited efficacy and considerable potential for adverse effects.[2] KChIP2 (Potassium Channel Interacting Protein 2) belongs to the calcium binding protein superfamily. It is the KChIP member predominantly expressed in heart and a key regulator of cardiac action potential duration. The identification of novel KChIP2 ligands could be useful to understand the role of KV4.3 channelosome in AF and it could help to discover new treatments for AF. [3] In this regard, structure-based virtual screening could be an important tool to accelerate the identification of novel KChIP2 ligands. In this communication, we will describe a multidisciplinary approach that, starting with a structurebased virtual screening, followed by an iterative process of synthesis/biological evaluation/docking studies, has led to the identification of new KChIP2 ligands.