6-Thioguanine is an anti-leukemia and immunosuppressant agent, acts as an inhibitor of SARS and MERS coronavirus papain-like proteases (PLpros) and also potently inhibits USP2 activity, with IC₅₀s of 25 μM and 40 μM for Plpros and recombinant human USP2, respectively.

IC50: 25 μM (PLpros), 40 μM (Recombinant human USP2)^[3]

6-Thioguanine is an anti-leukemia and immunosuppressant agent, acts as an inhibitor of SARS and MERS coronavirus papain-like proteases (PLpros) and also potently inhibits USP2 activity, with IC₅₀s of 25 μM and 40 μM for Plpros and recombinant human USP2, respectively^[1]. 6-Thioguanine affects the methylation of cytosine residues by purified DNA methyltransferases including human DNMT1 and bacterial HpaII methylase. 6-Thioguanine (1 or 3 μM) decreases global cytosine methylation in Jurkat T cells and cytosine methylation in human cells at 3 μM^[2]. 6-Thioguanine (18.75, 37.50, or 75.00 μM) adversely affects cell viability, but with no effect on LDH or ALT activity^[3].

• [1]. Chuang SJ, et al. 6-Thioguanine is a noncompetitive and slow binding inhibitor of human deubiquitinating protease USP2. Sci Rep. 2018 Feb 15;8(1):3102.

  [2]. Wang H, et al. 6-Thioguanine perturbs cytosine methylation at the CpG dinucleotide site by DNA methyltransferases in vitro and acts as a DNA demethylating agent in vivo. Biochemistry. 2009 Mar 17;48(10):2290-9.

  [3]. LaDuke KE, et al. Effects of azathioprine, 6-mercaptopurine, and 6-thioguanine on canine primary hepatocytes. Am J Vet Res. 2015 Jul;76(7):649-55.