ISG15 Inhibitors

ISG15 inhibitors belong to a distinct chemical class characterized by their ability to modulate the activity of the ISG15 protein. ISG15, short for Interferon-Stimulated Gene 15, is a small ubiquitin-like modifier (UBL) protein that plays a crucial role in the regulation of various cellular processes, particularly in the context of immune responses and antiviral defense mechanisms. The ISG15 protein is conjugated to target proteins in a process called ISGylation, analogous to ubiquitination, which often results in altered protein function, stability, or cellular localization. ISG15 inhibitors are compounds specifically designed to interfere with this conjugation process, thereby affecting the downstream effects of ISGylation on target proteins.

Structurally, ISG15 inhibitors are designed to interact with key enzymes involved in the ISGylation process, such as the E1-activating enzyme UBE1L and the E2-conjugating enzyme UBE2L6. By binding to these enzymes, ISG15 inhibitors disrupt the proper transfer of ISG15 onto target proteins, leading to a reduction in ISGylation-mediated effects. These inhibitors can act by various mechanisms, such as competitive inhibition at the active site of the enzymes or by inducing conformational changes that prevent effective enzyme-substrate interactions. Due to the pivotal role of ISG15 in regulating immune responses and antiviral activities, ISG15 inhibitors hold great potential in modulating cellular processes linked to inflammation, immune signaling, and viral infections.