SGC-CK2-1

SGC-CK2-1 A chemical probe for CK2

This probe is available from Tocris, Sigma and Cayman

This control is available from Sigma

  • overview
  • properties
  • selectivity profile
  • cell based assay data
  • references
overview
Probe Negative control

 

SGC-CK2-1

 

SGC-CK2-1N

Based upon a pyrazolopyrimidine scaffold with potent CK2 inhibition exemplified by AstraZeneca, the SGC has developed a high-quality chemical probe and its negative control for protein kinase CK2.1 This compound shows equal potency in binding to both catalytic subunits of CK2: CK2α (CSNK2A1) and  CK2α' (CSNK2A2). CK2 is a serine/threonine kinase that is part of the larger CMGC family, which is named after the initials of its subfamily members including cyclin-dependent kinases (CDK), mitogen-activated protein kinase (MAPK), glycogen synthase kinase (GSK), and CDC-like kinase (CLK). A plethora of biological functions have been ascribed to CK2 ranging from cell survival and proliferation to inflammation. CK2 phosphorylates more than 300 proteins and, via genetic and biochemical studies in a variety of experimental models, has been found to be both constitutively active and ubiquitously expressed.2-5 While CK2 inhibition has been widely studied in the context of cancer, pervasive use of non-selective CK2 inhibitors has confounded interpretation of results in many oncological studies.

Figure 1: Phylogenetic kinase tree with CK2α and CK2α' highlighted with red circles. Illustration is reproduced courtesy of Cell Signaling Technology, Inc. (www.cellsignal.com)

Key profiling data:

  • Enzymatic assays (Eurofins): CK2α IC50 = 4.2 nM; CK2α' IC50 = 2.3 nM at 10µM ATP
  • Cellular data (nanoBRET): CK2α IC50 = 36 nM; CK2α' IC50 = 16 nM
  • Only 11/403 kinases with PoC <35 when screened at 1 μM
properties
Probe

SGC-CK2-1

SMILES:
CC1=CC=C(C=C1NC(CC)=O)NC2=NC3=C(C=NN3C(NC4CC4)=C2)C#N
InChI:
InChI=1S/C20H21N7O/c1-3-19(28)25-16-8-15(5-4-12(16)2)23-17-9-18(24-14-6-7-14)27-20(26-17)13(10-21)11-22-27/h4-5,8-9,11,14,24H,3,6-7H2,1-2H3,(H,23,26)(H,25,28)
InChIKey: YKDZIFFKQUNVHH-UHFFFAOYSA-N

Physical and chemical properties
Molecular weight375.44
Molecular formulaC20 H21 N7 O
IUPAC nameN-(5-((3-cyano-7-(cyclopropylamino)pyrazolo[1,5-a]pyrimidin-5-yl)amino)-2-methylphenyl)propionamide
clogP1.94
PSA104.91
No. of chiral centres0
No. of rotatable bonds7
No. of hydrogen bond acceptors4
No. of hydrogen bond donors3
StorageStable as a solid at room temperature. DMSO stock solutions (up to 10 mM) are stable at -20oC
DissolutionSoluble up to 10mM in DMSO
Negative control

SGC-CK2-1N

SMILES:

CC1=CC=C(C=C1NC(C2CC2)=O)N(C3=NC4=C(C=NN4C(N(C5CC5)C)=C3)C#N)C
InChI:
InChI=1S/C23H25N7O/c1-14-4-7-18(10-19(14)26-23(31)15-5-6-15)28(2)20-11-21(29(3)17-8-9-17)30-22(27-20)16(12-24)13-25-30/h4,7,10-11,13,15,17H,5-6,8-9H2,1-3H3,(H,26,31)
InChIKey: LGMBLPOARZRSKR-UHFFFAOYSA-N

Physical and chemical properties
Molecular weight415.2
Molecular formulaC23 H25 N7 O
IUPAC name4-((3-(cyclopropyl-formylamino)-4-methyl-phenyl)-methyl-amino)-2-(cyclopropyl-methyl-amino)-1,5,9-triaza-bicyclo[4.3.0]nona-2,4,6,8-tetraene-7-carbonitrile
clogP3.67
PSA63.46
No. of chiral centres0
No. of rotatable bonds8
No. of hydrogen bond acceptors5
No. of hydrogen bond donors1
StorageStable as a solid at room temperature. DMSO stock solutions (up to 10 mM) are stable at -20oC
DissolutionSoluble up to 10mM in DMSO
selectivity profile

SGC-CK2-1 was profiled in the KINOMEscan assay against 403 wild-type kinases at 1 μM. Only 11 kinases showed PoC <35 giving an S(35) at 1 μM = 0.027. Potential off-targets were tested in the nanoBRET target engagement assay (DYRK2) and via Eurofins radiometric and LANCE kinase assays. Data corresponding with off-target kinase activity is shown in the table below.

 

Kinase% Control at 1µMEnzymatic IC50 (nM)NanoBRET IC50 (nM)
CK2α'/CSNK2A202.316
DRAK10>10000NT
CK2α/CSNK2A10.54.236
DYRK2144403700
PLK423>10000NT
HIPK2263400NT
MEK5280% AT 1µMNT
HIPK1323700NT
HIPK3348100NT
RIOK232NTNT
SGK334>10000NT

Figure 1: SGC-CK2-1 was profiled in the KINOMEscan assay against 403 wild-type kinases at 1 μM and off-target kinases inhibited PoC <35 were tested in an orthogonal assay.
 

SGC-CK2-1N was also tested in the DiscoverX panel and 1 kinase had a PoC <35. The negative control was sent to Eurofins for testing in enzyme assays for CSNK2A1 and CSNK2A2. The results are in the table below.

Kinase% Control at 1µMEnzymatic IC50 (nM)NanoBRET IC50 (nM)
RIOK123NTNT
RET35NTNT
FLT340NTNT
BRAF55NTNT
IKK-alpha58NTNT
MKNK158NTNT
STK3361NTNT
TNK162NTNT
EPHA263NTNT
CK2α'/CSNK2A265>10000>10000
CK2α/CSNK2A1100>10000NT

Figure 2: SGC-CK2-1N was profiled in the KINOMEscan assay against 403 wild-type kinases at 1 μM and follow-up CK2α and CK2α' enzymatic assays were done to confirm no activity.

in vitro potency
cell based assay data

A NanoBRET assay was utilized to assess the binding affinity of SGC-CK2-1 to CK2α and CK2α'. The negative control shows no binding affinity for CK2α'.

Figure 1: SGC-CK2-1 and SGC-CK2-1N were profiled in the CK2 NanoBRET assays.

references
  1. Wells, C., Drewry, D. H., Pickett, J. E. & Axtman, A. D. SGC-CK2-1: the first selective chemical probe for the pleiotropic kinase CK2. ChemRxiv, 10.26434/chemrxiv.12296180.v12296181 (2020).
  2. Rabalski, A. J., Gyenis, L. & Litchfield, D. W. Molecular Pathways: Emergence of Protein Kinase CK2 (CSNK2) as a Potential Target to Inhibit Survival and DNA Damage Response and Repair Pathways in Cancer Cells. Clinical Cancer Research 22, 2840-2847, doi:10.1158/1078-0432.Ccr-15-1314 (2016).
  3. Meggio, F. & Pinna, L. A. One-thousand-and-one substrates of protein kinase CK2? FASEB journal : official publication of the Federation of American Societies for Experimental Biology 17, 349-368, doi:10.1096/fj.02-0473rev (2003).
  4. Nuñez de Villavicencio-Diaz, T., Rabalski, A. J. & Litchfield, D. W. Protein Kinase CK2: Intricate Relationships within Regulatory Cellular Networks. Pharmaceuticals 10, 27 DOI: 10.3390/ph10010027 (2017).
  5. Ahmed, K., Gerber, D. A. & Cochet, C. Joining the cell survival squad: an emerging role for protein kinase CK2. Trends in Cell Biology 12, 226-230, doi:10.1016/S0962-8924(02)02279-1 (2002).

Related Links: https://www.tocris.com/products/sgc-ck2-1_7450#product-literature

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