IC50= 0.1 μM; Ki= 40 nM

TTP 22 is a high affinity, ATP-competitive casein kinase 2 (CK2) inhibitor.

Casein kinase 2 (CK2) noticeably stands out against a background of the kinase family due to its constitutive catalytic activity with the ability to phosphorylate more than 300 physiological substrates. These features make CK2 appear greatly diverse points of cell signaling pathways and be involved in processes leading to the development of various disorders, especially cancer. Thus, currently CK2 is regarded as druggable protein kinase target and can be used for the development of antitumor, anti-inflammatory and antiviral drugs.

In vitro: Kinetic studies of TTP 22 showed that activity of (thieno[2,3-d]pyrimidin-4-ylthio)carboxylic acids moiety was a result of its competition with ATP molecule for the binding site. Inhibition constant (Ki) for TTP 22 was 40 nM. Initial in vitro tests of TTP 22 and it analog on four serine/threonine (ASK1, JNK3, Aurora A and Rock 1) and three tyrosine protein kinases (FGFR1, Met and Tie2) revealed their remarkable specificity towards CK2 [1].

In vivo: So far, no animal in vivo study has been conducted for TTP 22.

Clinical trial: N/A

Reference:
[1] Golub AG,Bdzhola VG,Briukhovetska NV,Balanda AO,Kukharenko OP,Kotey IM,Ostrynska OV,Yarmoluk SM.  Synthesis and biological evaluation of substituted (thieno[2,3-d]pyrimidin-4-ylthio)carboxylic acids as inhibitors of human protein kinase CK2. Eur J Med Chem.2011 Mar;46(3):870-6.