Hemoglobinopathies remain a major global healthcare challenge in the modern world, with treatments focusing only on managing the symptoms of the disease and not on completely tackling the underlying cause. One promising approach to treat these diseases is via the reactivation of γ-globin, which after birth is silenced by the chromatin remodelling enzyme, CHD4. It has been shown that mutations that prevent the silencing of γ-globin protect people who would normally suffer hemoglobinopathies. Thus, CHD4 is a promising drug target to be explored further. Recent work in our group has explored the roles of each domain within the CHD4. A potential target for inhibition within CHD4 is the C-terminal domain, which we propose to play a key role in nucleosome binding and the regulation of remodelling activity.
In this research, we aim to design a cyclic peptide inhibitor targeted to the C-terminal domain of CHD4. We are using the Random nonstandard Integrated Peptide Discovery (RaPID) platform to generate candidate inhibitors. This technology integrates mRNA display with a flexible in-vitro translation system, allowing a rapid screening of large amount of peptide libraries and the incorporation of non-natural amino acids to drive cyclization. The binding properties of the most promising candidates will be assessed using surface plasmon resonance (SPR) and the mechanism underlying binding for chosen candidates will be determined by X-ray crystallography. The ability of the best peptides to inhibit CHD4 activity will be determined in an in vitro chromatin remodelling assay and in a cell-based assay for γ-globin reactivation.