Glutathione S Transferase Kappa 1 (GSTk1) is a member of the GST superfamily. It has unique enzymatic activities and plays important roles in cellular detoxification and protection against oxidative stress. GSTk1 is involved in conjugating glutathione to a variety of substrates, facilitating the removal of harmful substances from cells. It is expressed in different tissues and has been implicated in various physiological and pathological processes. Its functions are crucial for maintaining cellular homeostasis and overall organismal health.Besides,the binding of GSTk1 and CDK2 may regulate cell cycle progression and affect cell proliferation, potentially influencing tumor development and other cellular events.Thus a functional ELISA assay was conducted to detect the interaction of recombinant human GSTk1 and recombinant mouse CDK2. Briefly, GSTk1 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to CDK2-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-GSTk1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 μL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant human GSTk1 and recombinant mouse CDK2 was shown in Figure 1, the EC50?for this effect is 0.046ug/mL.