7REN

Room temperature serial crystal structure of Glutaminase C in complex with inhibitor UPGL-00004

Summary for 7REN

• Entry DOI: 10.2210/pdb7ren/pdb
• Descriptor: Glutaminase kidney isoform, mitochondrial, 2-phenyl-N-{5-[4-({5-[(phenylacetyl)amino]-1,3,4-thiadiazol-2-yl}amino)piperidin-1-yl]-1,3,4-thiadiazol-2-yl}acetamide (3 entities in total)
• Functional Keywords: hydrolase-inhibitor complex, hydrolase/inhibitor
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 4
• Total formula weight: 238899.67

Authors

Milano, S.K.,Finke, A.,Cerione, R.A. (deposition date: 2021-07-13, release date: 2022-05-25, Last modification date: 2023-10-18)

Primary citation

Milano, S.K.,Huang, Q.,Nguyen, T.T.,Ramachandran, S.,Finke, A.,Kriksunov, I.,Schuller, D.J.,Szebenyi, D.M.,Arenholz, E.,McDermott, L.A.,Sukumar, N.,Cerione, R.A.,Katt, W.P.
New insights into the molecular mechanisms of glutaminase C inhibitors in cancer cells using serial room temperature crystallography.
J.Biol.Chem., 298:101535-101535, 2022

PubMed Abstract: Cancer cells frequently exhibit uncoupling of the glycolytic pathway from the TCA cycle (i.e., the "Warburg effect") and as a result, often become dependent on their ability to increase glutamine catabolism. The mitochondrial enzyme Glutaminase C (GAC) helps to satisfy this 'glutamine addiction' of cancer cells by catalyzing the hydrolysis of glutamine to glutamate, which is then converted to the TCA-cycle intermediate α-ketoglutarate. This makes GAC an intriguing drug target and spurred the molecules derived from bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (the so-called BPTES class of allosteric GAC inhibitors), including CB-839, which is currently in clinical trials. However, none of the drugs targeting GAC are yet approved for cancer treatment and their mechanism of action is not well understood. Here, we shed new light on the underlying basis for the differential potencies exhibited by members of the BPTES/CB-839 family of compounds, which could not previously be explained with standard cryo-cooled X-ray crystal structures of GAC bound to CB-839 or its analogs. Using an emerging technique known as serial room temperature crystallography, we were able to observe clear differences between the binding conformations of inhibitors with significantly different potencies. We also developed a computational model to further elucidate the molecular basis of differential inhibitor potency. We then corroborated the results from our modeling efforts using recently established fluorescence assays that directly read out inhibitor binding to GAC. Together, these findings should aid in future design of more potent GAC inhibitors with better clinical outlook.

PubMed: 34954143
DOI: 10.1016/j.jbc.2021.101535

Experimental method

X-RAY DIFFRACTION (2.8 Å)