Jonggul Kim

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Conformational fluctuations play a central role in enzymatic catalysis. However, it is not clear how the rates and the coordination of the motions affect the different catalytic steps. Here, we used NMR spectroscopy to analyze the conformational fluctuations of the catalytic subunit of the cAMP-dependent protein kinase (PKA-C), a ubiquitous enzyme involved(More)
The canonical function of kinases is to transfer a phosphoryl group to substrates, initiating a signaling cascade; while their non-canonical role is to bind other kinases or substrates, acting as scaffolds, competitors, and signal integrators. Here, we show how to uncouple kinases' dual function by tuning the binding cooperativity between nucleotide (or(More)
The dynamic interplay between kinases and substrates is crucial for the formation of catalytically committed complexes that enable phosphoryl transfer. However, a clear understanding on how substrates modulate kinase structural dynamics to control catalytic efficiency is still missing. Here, we used solution NMR spectroscopy to study the conformational(More)
Proteins exist as an ensemble of conformers that are distributed on free energy landscapes resembling folding funnels. While the most stable conformers populate low energy basins, protein function is often carried out through low-populated conformational states that occupy high energy basins. Ligand binding shifts the populations of these states, changing(More)
We present an enhanced version of the FLAMEnGO (Fuzzy Logic Assignment of Methyl Group) software, a structure-based method to assign methyl group resonances in large proteins. FLAMEnGO utilizes a fuzzy logic algorithm coupled with Monte Carlo sampling to obtain a probability-based assignment of the methyl group resonances. As an input, FLAMEnGO requires(More)
Protein kinase A is a prototypical phosphoryl transferase, sharing its catalytic core (PKA-C) with the entire kinase family. PKA-C substrate recognition, active site organization, and product release depend on the enzyme's conformational transitions from the open to the closed state, which regulate its allosteric cooperativity. Here, we used equilibrium(More)
Leukocytes have been investigated during the past decade for their roles in secondary tissue damage after ischemia/reperfusion injury. Peptide PRARIY, a synthetic fibronectin peptide, has shown an anti-adhesion effect in in vitro studies. Previous studies have demonstrated that anti-adhesion agents lead to reductions in apoptosis. The purpose of the present(More)
Eukaryotic protein kinases (EPKs) constitute a class of allosteric switches that mediate a myriad of signaling events. It has been postulated that EPKs' active and inactive states depend on the structural architecture of their hydrophobic cores, organized around two highly conserved spines: C-spine and R-spine. How the spines orchestrate the transition of(More)
The developments of biosynthetic specific labeling strategies for side-chain methyl groups have allowed structural and dynamic characterization of very large proteins and protein complexes. However, the assignment of the methyl-group resonances remains an Achilles' heel for NMR, as the experiments designed to correlate side chains to the protein backbone(More)
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