The SARS-CoV-2 coronavirus encodes a papain-like cysteine protease PLpro (NSP3) that cleaves the viral polyprotein, removes ubiquitin-like ISG15 protein modifications and (with lower activity) Lys48-linked polyubiquitin chains. As PLPro is essential for SARS-CoV-2 replication, it represents a promising target for the development of antiviral drugs. In light of this and to complement our well-known ubiquitin based reagents, we are expanding our portfolio of ISG15 based reagents. Recently we developed the fluorescence polarization assay reagent UbiQ-287 (short name hISG15 FP). This is based on full-length human ISG15 that is linked via an isopeptide bond to a 5-carboxytetramethylrhodamine (TAMRA, exc/emi 550/590 nm) functionalized dipeptide (Figure 1).
Figure 1. Human ISG15 FP reagent UbiQ-287.
Below we have listed our current portfolio of ISG15 based reagents.