Ubiquitin Specific Peptidase 7 (USP7) is a deubiquitinating enzyme that plays a crucial role in the ubiquitin - proteasome system. It specifically cleaves ubiquitin from target proteins, thereby regulating their stability, localization, and function. USP7 has been shown to interact with numerous proteins involved in various cellular processes, including cell cycle regulation, DNA repair, and apoptosis. By removing ubiquitin tags, USP7 can prevent the degradation of key regulatory proteins, allowing them to continue their functions within the cell. Additionally, USP7 is involved in the regulation of viral infections, as it can deubiquitinate viral proteins and affect their replication and pathogenesis.Furthermore,USP7 can bind and deubiquitinate UBA52, a ubiquitin-ribosomal fusion protein, influencing ribosomal function and protein synthesis. This interaction links USP7 to translational regulation and cellular homeostasis.Thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human USP7 and recombinant human UBA52 .Briefly, biotin-linked USP7 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to UBA52-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50μl stop solution to the wells and read at 450nm immediately. The binding activity of recombinant human USP7 and recombinant human UBA52 was shown in Figure 1, the EC50?for this effect is 0.107ug/mL.