scholarly journals A High-Throughput Screening Triage Workflow to Authenticate a Novel Series of PFKFB3 Inhibitors

2017 ◽  
Vol 23 (1) ◽  
pp. 11-22
Author(s):  
Stephen A. St-Gallay ◽  
Neil Bennett ◽  
Susan E. Critchlow ◽  
Nicola Curtis ◽  
Gareth Davies ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Isothermal Calorimetry ◽  
Binding Mode ◽  
Carbonyl Oxygen ◽  
Enzyme Concentration ◽  
Titration Calorimetry ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Hill

A high-throughput screen (HTS) of human 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) resulted in several series of compounds with the potential for further optimization. Informatics was used to identify active chemotypes with lead-like profiles and remove compounds that commonly occurred as actives in other HTS screens. The activities were confirmed with IC50 measurements from two orthogonal assay technologies, and further analysis of the Hill slopes and comparison of the ratio of IC50 values at 10 times the enzyme concentration were used to identify artifact compounds. Several series of compounds were rejected as they had both high slopes and poor ratios. A small number of compounds representing the different leading series were assessed using isothermal titration calorimetry, and the X-ray crystal structure of the complex with PFKFB3 was solved. The orthogonal assay technology and isothermal calorimetry were demonstrated to be unreliable in identifying false-positive compounds in this case. Presented here is the discovery of the dihydropyrrolopyrimidinone series of compounds as active and novel inhibitors of PFKFB3, shown by X-ray crystallography to bind to the adenosine triphosphate site. The crystal structures of this series also reveal it is possible to flip the binding mode of the compounds, and the alternative orientation can be driven by a sigma-hole interaction between an aromatic chlorine atom and a backbone carbonyl oxygen. These novel inhibitors will enable studies to explore the role of PFKFB3 in driving the glycolytic phenotype of tumors.

Metabolic intervention targeting 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) using a structure-based design.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13518-e13518
Author(s):  
Lars Ährlund-Richter ◽  
Katarina Färnegårdh ◽  
Elisee Wiita ◽  
Mattias Jönsson ◽  
Carina Norström ◽  
...  
Keyword(s):  
Cell Growth ◽  
High Throughput ◽  
High Throughput Screening ◽  
Structural Information ◽  
Human Cancer ◽  
Isothermal Calorimetry ◽  
Binding Pocket ◽  
Binding Modes ◽  
X Ray ◽  
X Ray Crystallography

e13518 Background: By producing fructose-2,6-bisphosphate, PFKFB3 functions as an activator of anaerobic glycolysis. PFKFB3 is both over expressed and over activated in many of the types of human cancer. Specific inhibition of the PFKFB3 enzyme results in a reduction in metabolism and cell growth in oxygen-deficient cancer environments. Methods: High-throughput screening. Medicinal Chemistry. Structure-Based Drug Design, X-ray Crystallography. NMR. Isothermal Calorimetry. Dynamic Light Scatttering. ADME. Results: A high-throughput screening of 50.000 selected compounds, by means of a biochemical assay, generated 105 hits including both ATP-and non-ATP competitive hits as identified by NMR binding experiments. The latter type was prioritized and two hits with a similar “ring-linker-ring structure” were selected for further expansions. Interestingly, although structurally similar, the two hits were found by means of X-ray crystallography to exhibit different binding modes within the fructose pocket. Based on their respective binding mode, two chemical series were developed displaying different ADME properties and PFKFB isoenzyme selectivity. Calorimetry verified a reversible strong enthalpy driven, direct binding for both chemical series. A third chemical series was developed towards yet another unoccupied binding pocket within the fructose-site, yielding a 5-fold increase in potency. Strong interactions within the new pocket were confirmed using X-ray crystallography. Our PFKFB3 inhibitors were shown to reduce tumor cell growth in vitro and to exhibit combinatory effects with Cisplatin. Conclusions: We have targeted the fructose-binding pocket of PFKFB3, developed compounds with nM binding potency and have gained a detailed understanding of SAR via structural information. The structure-based analysis has provided a good understanding of the molecular interactions, which is important for further biological/clinical positioning: e.g., combination with chemotherapy, optimization of PK properties and proof of principle in vivo.

scholarly journals Fragment-based screening by X-ray crystallography: an alternative to high throughput screening

2005 ◽  
Vol 61 (a1) ◽  
pp. c246-c246
Author(s):  
A. Cleasby ◽  
L. Devine ◽  
M. Frederickson ◽  
M. Hartshorn ◽  
I. Tickle ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Searching novel complex solid solution electrocatalysts in unconventional element combinations

Nano Research ◽  
2021 ◽  
Author(s):  
Olga A. Krysiak ◽  
Simon Schumacher ◽  
Alan Savan ◽  
Wolfgang Schuhmann ◽  
Alfred Ludwig ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Active Sites ◽  
Search Space ◽  
Reduction Reaction ◽  
Film Material ◽  
X Ray ◽  
High Entropy ◽  
Catalyst Composition ◽  
Scanning Transmission

AbstractDespite outstanding accomplishments in catalyst discovery, finding new, more efficient, environmentally neutral, and noble metal-free catalysts remains challenging and unsolved. Recently, complex solid solutions consisting of at least five different elements and often named as high-entropy alloys have emerged as a new class of electrocatalysts for a variety of reactions. The multicomponent combinations of elements facilitate tuning of active sites and catalytic properties. Predicting optimal catalyst composition remains difficult, making testing of a very high number of them indispensable. We present the high-throughput screening of the electrochemical activity of thin film material libraries prepared by combinatorial co-sputtering of metals which are commonly used in catalysis (Pd, Cu, Ni) combined with metals which are not commonly used in catalysis (Ti, Hf, Zr). Introducing unusual elements in the search space allows discovery of catalytic activity for hitherto unknown compositions. Material libraries with very similar composition spreads can show different activities vs. composition trends for different reactions. In order to address the inherent challenge of the huge combinatorial material space and the inability to predict active electrocatalyst compositions, we developed a high-throughput process based on co-sputtered material libraries, and performed high-throughput characterization using energy dispersive X-ray spectroscopy (EDS), scanning transmission electron microscopy (SEM), X-ray diffraction (XRD) and conductivity measurements followed by electrochemical screening by means of a scanning droplet cell. The results show surprising material compositions with increased activity for the oxygen reduction reaction and the hydrogen evolution reaction. Such data are important input data for future data-driven materials prediction.

scholarly journals G-Quadruplexes and Their Ligands: Biophysical Methods to Unravel G-Quadruplex/Ligand Interactions

2021 ◽  
Vol 14 (8) ◽  
pp. 769
Author(s):  
Tiago Santos ◽  
Gilmar F. Salgado ◽  
Eurico J. Cabrita ◽  
Carla Cruz
Keyword(s):  
High Throughput ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Binding Mode ◽  
Titration Calorimetry ◽  
Apparent Affinity ◽  
G Quadruplex ◽  
Ligand Interactions ◽  
Types Of Information ◽  
Fluorescent Intercalator Displacement

Progress in the design of G-quadruplex (G4) binding ligands relies on the availability of approaches that assess the binding mode and nature of the interactions between G4 forming sequences and their putative ligands. The experimental approaches used to characterize G4/ligand interactions can be categorized into structure-based methods (circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography), affinity and apparent affinity-based methods (surface plasmon resonance (SPR), isothermal titration calorimetry (ITC) and mass spectrometry (MS)), and high-throughput methods (fluorescence resonance energy transfer (FRET)-melting, G4-fluorescent intercalator displacement assay (G4-FID), affinity chromatography and microarrays. Each method has unique advantages and drawbacks, which makes it essential to select the ideal strategies for the biological question being addressed. The structural- and affinity and apparent affinity-based methods are in several cases complex and/or time-consuming and can be combined with fast and cheap high-throughput approaches to improve the design and development of new potential G4 ligands. In recent years, the joint use of these techniques permitted the discovery of a huge number of G4 ligands investigated for diagnostic and therapeutic purposes. Overall, this review article highlights in detail the most commonly used approaches to characterize the G4/ligand interactions, as well as the applications and types of information that can be obtained from the use of each technique.

Chapter 3 High-Throughput Protein Purification for X-Ray Crystallography and NMR

2008 ◽  
pp. 85-105
Author(s):  
Youngchang Kim ◽  
Lance Bigelow ◽  
Maria Borovilos ◽  
Irina Dementieva ◽  
Erika Duggan ◽  
...  
Keyword(s):  
Protein Purification ◽  
High Throughput ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Using Weighted Entropy to Rank Chemicals in Quantitative High-Throughput Screening Experiments

2013 ◽  
Vol 19 (3) ◽  
pp. 344-353 ◽  
Author(s):  
Keith R. Shockley
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Nonlinear Models ◽  
Hill Equation ◽  
Parameter Estimates ◽  
Chemical Library ◽  
Data Set ◽  
Screening Experiments ◽  
The Hill ◽  
Weighted Entropy

Quantitative high-throughput screening (qHTS) experiments can simultaneously produce concentration-response profiles for thousands of chemicals. In a typical qHTS study, a large chemical library is subjected to a primary screen to identify candidate hits for secondary screening, validation studies, or prediction modeling. Different algorithms, usually based on the Hill equation logistic model, have been used to classify compounds as active or inactive (or inconclusive). However, observed concentration-response activity relationships may not adequately fit a sigmoidal curve. Furthermore, it is unclear how to prioritize chemicals for follow-up studies given the large uncertainties that often accompany parameter estimates from nonlinear models. Weighted Shannon entropy can address these concerns by ranking compounds according to profile-specific statistics derived from estimates of the probability mass distribution of response at the tested concentration levels. This strategy can be used to rank all tested chemicals in the absence of a prespecified model structure, or the approach can complement existing activity call algorithms by ranking the returned candidate hits. The weighted entropy approach was evaluated here using data simulated from the Hill equation model. The procedure was then applied to a chemical genomics profiling data set interrogating compounds for androgen receptor agonist activity.

scholarly journals Fragment-Based Screening for Inhibitors of PDE4A Using Enthalpy Arrays and X-ray Crystallography

2012 ◽  
Vol 17 (4) ◽  
pp. 469-480 ◽  
Author(s):  
Michael I. Recht ◽  
Vandana Sridhar ◽  
John Badger ◽  
Leslie Hernandez ◽  
Barbara Chie-Leon ◽  
...  
Keyword(s):  
Spectroscopic Properties ◽  
Titration Calorimetry ◽  
Label Free ◽  
Lead Discovery ◽  
High Resolution Data ◽  
Affinity Ligands ◽  
X Ray ◽  
X Ray Crystallography ◽  
Chemical Structures ◽  
Fragment Library

Fragment-based screening has typically relied on X-ray or nuclear magnetic resonance methods to identify low-affinity ligands that bind to therapeutic targets. These techniques are expensive in terms of material and time, so it useful to have a higher throughput method to reliably prescreen a fragment library to identify a subset of compounds for structural analysis. Calorimetry provides a label-free method to assay binding and enzymatic activity that is unaffected by the spectroscopic properties of the sample. Conventional microcalorimetry is hampered by requiring large quantities of reagents and long measurement times. Nanocalorimeters can overcome these limitations of conventional isothermal titration calorimetry. Here we have used enthalpy arrays, which are arrays of nanocalorimeters, to perform an enzyme activity-based fragment screen for competitive inhibitors of phosphodiesterase 4A (PDE4A). Several inhibitors with K I <2 mM were identified and moved to X-ray crystallization trials. Although the co-crystals did not yield high-resolution data, evidence of binding was observed, and the chemical structures of the hits were consistent with motifs of known PDE4 inhibitors. This study shows how array calorimetry can be used as a prescreening method for fragment-based lead discovery with enzyme targets and provides a list of candidate fragments for inhibition of PDE4A.

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