PDBsum entry 4m13

Transferase/transferase inhibitor

PDB id: 4m13

Contents

Protein chain

264 a.a.

Ligands

1E0

Waters ×189

PDB id:

4m13

Name:

Transferase/transferase inhibitor

Title:

Crystal structure of itk in complex with compound 8 [4- (carbamoylamino)-1-(7-propoxynaphthalen-1-yl)-1h-pyrazole-3- carboxamide]

Structure:

Tyrosine-protein kinase itk/tsk. Chain: a. Fragment: unp residues 354-620. Synonym: interleukin-2-inducible t-cell kinase, il-2-inducible t-cell kinase, kinase emt, t-cell-specific kinase, tyrosine-protein kinase lyk. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: itk, emt, lyk. Expressed in: spodoptera frugiperda. Expression_system_taxid: 7108

Resolution:

1.85Å R-factor: 0.190 R-free: 0.232

Authors:

S.Han,N.L.Caspers

Key ref:

S.Han et al. (2014). Selectively targeting an inactive conformation of interleukin-2-inducible T-cell kinase by allosteric inhibitors. Biochem J, 460, 211-222. PubMed id: 24593284 DOI: 10.1042/BJ20131139

Date:

02-Aug-13 Release date: 02-Apr-14

Protein chain

Q08881  (ITK_HUMAN) -  Tyrosine-protein kinase ITK/TSK from Homo sapiens

Seq: 620 a.a.

Struc: 264 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.7.10.2 - non-specific protein-tyrosine kinase.
• Reaction: L-tyrosyl-[protein] + ATP = O-phospho-L-tyrosyl-[protein] + ADP + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

DOI no: 10.1042/BJ20131139

Biochem J 460:211-222 (2014)

PubMed id: 24593284

Selectively targeting an inactive conformation of interleukin-2-inducible T-cell kinase by allosteric inhibitors.

S.Han, R.M.Czerwinski, N.L.Caspers, D.C.Limburg, W.Ding, H.Wang, J.F.Ohren, F.Rajamohan, T.J.McLellan, R.Unwalla, C.Choi, M.D.Parikh, N.Seth, J.Edmonds, C.Phillips, S.Shakya, X.Li, V.Spaulding, S.Hughes, A.Cook, C.Robinson, J.P.Mathias, I.Navratilova, Q.G.Medley, D.R.Anderson, R.G.Kurumbail, A.Aulabaugh.

ABSTRACT

ITK (interleukin-2-inducible T-cell kinase) is a critical component of signal transduction in T-cells and has a well-validated role in their proliferation, cytokine release and chemotaxis. ITK is an attractive target for the treatment of T-cell-mediated inflammatory diseases. In the present study we describe the discovery of kinase inhibitors that preferentially bind to an allosteric pocket of ITK. The novel ITK allosteric site was characterized by NMR, surface plasmon resonance, isothermal titration calorimetry, enzymology and X-ray crystallography. Initial screening hits bound to both the allosteric pocket and the ATP site. Successful lead optimization was achieved by improving the contribution of the allosteric component to the overall inhibition. NMR competition experiments demonstrated that the dual-site binders showed higher affinity for the allosteric site compared with the ATP site. Moreover, an optimized inhibitor displayed non-competitive inhibition with respect to ATP as shown by steady-state enzyme kinetics. The activity of the isolated kinase domain and auto-activation of the full-length enzyme were inhibited with similar potency. However, inhibition of the activated full-length enzyme was weaker, presumably because the allosteric site is altered when ITK becomes activated. An optimized lead showed exquisite kinome selectivity and is efficacious in human whole blood and proximal cell-based assays.