T-705RTP sodium is a selective and GTP-competitive influenza virus RNA polymerase inhibitor with an IC50 of 0.14 μM and a Ki of 1.52 μM. T-705RTP sodium is the active triphosphate metabolite of T-705 and has potent anti-influenza virus activity[1][2].
T-705RTP sodium and T-705RMP are detected in MDCK cells treated with T-705. T-705RTP sodium inhibits influenza virus RNA polymerase activity in a dose-dependent and a GTP-competitive manner[1]. T-705RTP sodium inhibits the incorporation of ATP and GTP in a competitive manner with Ki values of 7.72 and 1.56 μM, respectively. T-705RTP sodium inhibits the incorporation of CTP in a mixed-type manner with a Ki value of 11.3 μM, and also inhibits the incorporation of UTP in a noncompetitive manner[2]. The incorporation of a single molecule of T-705RTP sodium (10-1000 μM) inhibits influenza virus RNA strand extension[2].
[1]. Furuta Y, et al. Mechanism of action of T-705 against influenza virus. Antimicrob Agents Chemother. 2005 Mar;49(3):981-6. [2]. Sangawa H, et al. Mechanism of action of T-705 ribosyl triphosphate against influenza virus RNA polymerase. Antimicrob Agents Chemother. 2013 Nov;57(11):5202-8.