Related Experiment Video

Updated: Dec 30, 2025

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors
12:40

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors

Published on: December 7, 2014

15.1K

Insights into the Binding Recognition and Susceptibility of Tofacitinib toward Janus Kinases

Kamonpan Sanachai1, Panupong Mahalapbutr1, Kiattawee Choowongkomon2

  • 1Structural and Computational Biology Research Unit, Department of Biochemistry, Faculty of Science and Program in Bioinformatics and Computational Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.

ACS Omega
|January 21, 2020
PubMed

Insights

Tofacitinib effectively binds to Janus kinases (JAKs) 1, 2, and 3 through key interactions in the ATP-binding site. This study reveals JAK3 exhibits the highest binding affinity, aligning with experimental findings.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Pharmacology

Background:

  • Janus kinases (JAKs) are crucial enzymes regulating hematopoiesis and immune responses.
  • JAK family members (JAK1, JAK2, JAK3) are implicated in various immune diseases and cancer.
  • JAK inhibitors represent a therapeutic strategy for these conditions.

Purpose of the Study:

  • To investigate the binding susceptibility of the oral JAK inhibitor tofacitinib against JAK1, JAK2, and JAK3.
  • To elucidate the molecular interactions and binding affinities of tofacitinib with these JAKs.

Main Methods:

  • Employed 500-ns molecular dynamics (MD) simulations.
  • Utilized free energy calculations including MM-PB(GB)SA, QM/MM-GBSA (PM3 and SCC-DFTB), and SIE methods.

Main Results:

  • Tofacitinib interacts with all JAKs at the ATP-binding site via electrostatic, hydrogen bond, and van der Waals interactions.
  • Conserved residues in the hinge region (glutamate and leucine) stabilize tofacitinib binding through hydrogen bonds.
  • Binding of tofacitinib induced a closed conformation of the ATP-binding site and reduced protein fluctuation.
  • Binding affinities were ranked as JAK3 > JAK2 ∼ JAK1, consistent with experimental data.

Conclusions:

  • Tofacitinib exhibits significant binding interactions with JAK1, JAK2, and JAK3.
  • The molecular dynamics and binding free energy calculations provide insights into tofacitinib's inhibitory mechanism.
  • The differential binding affinities support the targeted therapeutic potential of tofacitinib across JAK family members.

More Related Videos

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-308:36

Scaled-Up Preparation of an Intermediate of Upatinib, ACT051-3

Published on: April 7, 2023

1.4K
Kinase Inhibitor Screening In Self-assembled Human Protein Microarrays13:22

Kinase Inhibitor Screening In Self-assembled Human Protein Microarrays

Published on: October 23, 2019

8.2K

Related Concept Videos

The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
11.6K
NF-κB-dependent Signaling Pathway02:26

NF-κB-dependent Signaling Pathway

The transcription factor NF-κB was discovered in 1986 in the lab of Nobel laureate Professor David Baltimore, for its interaction with the immunoglobulin light chain enhancer in B-cells. After more than three decades of study, it is now evident that NF-κB regulates the expression of over 100 genes. Most of these genes play an essential role in the innate and adaptive immune responses as well as the inflammatory responses of animals.
NF-κB-dependent Signaling Mechanism
The...
9.7K
TGF - β Signaling Pathway01:16

TGF - β Signaling Pathway

The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors...
10.3K
Receptor Tyrosine Kinases01:26

Receptor Tyrosine Kinases

Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
17.5K
cAMP-dependent Protein Kinase Pathways01:25

cAMP-dependent Protein Kinase Pathways

Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
8.1K
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
7.7K