Identification of protein partners for small molecules reshapes the understanding of nonalcoholic steatohepatitis and drug discovery

Nonalcoholic steatohepatitis (NASH) is the severe subtype of nonalcoholic fatty diseases (NAFLD) with few options of treatment. Patients with NASH exhibit partial responses to the current therapeutics, and adverse effects. Identification of the binding proteins for the drugs is essential to understanding the mechanism and adverse effects of the drugs, and fuels the discovery of potent and safe drugs. This paper aims to critically discuss recent advances in covalent and noncovalent approaches for identifying binding proteins that mediate NASH progression, along with an in-depth analysis of the mechanisms by which these targets regulate NASH. A literature search was conducted to identify the relevant studies in the database of PubMed and American Chemical Society. The search covered articles published from January 1990 to July 2024, using the search terms of with the keywords such as NASH, benzophenone, diazirine, photo-affinity labeling, thermal protein profiling, CETSA, target identification. The covalent approaches utilize drugs modified with diazirine and benzophenone to covalently crosslink with the target proteins, which facilitates the purification and identification of target proteins. In addition, they map the binding sites in the target proteins. By contrast, noncovalent approaches identify the binding targets of unmodified drugs in the intact cell proteome. The advantages and limitations of both approaches have been compared, along with a comprehensive analysis of recent innovations that further enhance the efficiency and specificity. The analyses of the applicability of these approaches provide novel tools to delineate NASH pathogenesis and promotes drug discovery.