The Acid-sensing ion channel isoform 1a (ASIC1a) is implicated in various conditions, including heart attacks, strokes, and other neurodegenerative disorders. Genetic ablation and subsequent studies using venom-derived peptide toxins have shown protective effects, with clinical trials underway for some of these candidates. One particularly unique molecule is Hi1a, a double-inhibitory cysteine knot (ICK) peptide known for its remarkable selectivity, potency, and irreversibility. Due to its promising attributes, significant interest surrounds its mechanism of action and potential for clinical applications. However, challenges related to the synthesis and practicality of both the molecular target and ligand have hindered the acquisition of an accurate crystal structure and furthered structure activity relationship (SAR) studies.
In my research, I have concentrated on developing a versatile pipeline to elucidate the mechanisms of action of peptides binding to unknown sites, utilising various freely available tools and the ASIC1a-Hi1a complex as a model. Throughout this process, I have created precise neuronal membrane systems based on a multitude of AlphaFold2 predictions. These systems mimic the native environment of ASIC1a-Hi1a and have undergone simulations to identify potential binding sites. Additionally, I have assessed the impact of known detrimental mutations within the simulation and from this, I have developed a hypothesis regarding the binding site. Currently, this hypothesis is undergoing in-vitro evaluation. This work aims to contribute to the development of novel therapeutics for ASIC1a and can potentially be extended to similar peptide-protein complexes.