Approaches to Automating the Dereplication of Bioactive Natural Products—The Key Step in High Throughput Screening of Bioactive Materials From Natural Sources

1997 ◽  
Vol 2 (3) ◽  
pp. 145-152 ◽  
Author(s):  
Derek J. Hook ◽  
Edward J. Pack ◽  
Joseph J. Yacobucci ◽  
Jeffrey Guss

The rapid identification of the bioactive component(s) of natural product mixtures in high throughput screening programs has become a critical factor to ensure that this source of diverse chemotypes can compete effectively with chemical compound libraries and combinatorial synthetic efforts. The effective use of automated procedures and databases in the isolation, identification and biological profiling of bioactive compounds will be described. In addition, the potential of new technologies to enhance this process will be discussed as well as the possible reintroduction of TLC as a parallel dereplication method.

2000 ◽  
Vol 22 (5) ◽  
pp. 149-157 ◽  
Author(s):  
Ralf Thiericke

Secondary metabolites from plants, animals and microorganisms have been proven to be an outstanding source for new and innovative drugs and show a striking structural diversity that supplements chemically synthesized compounds or libraries in drug discovery programs. Unfortunately, extracts from natural sources are usually complex mixtures of compounds:: often generated in time consuming and for the most part manual processes. As quality and quantity of the provided samples play a pivotal role in the success of high-throughput screening programs this poses serious problems. In order to make samples of natural origin competitive with synthetic compound libraries, we devised a novel, automated sample preparation procedure based on solid-phase extraction (SPE). By making use of a modified Zymark RapidTrace®SPE workstation an easy-to-handle and effective fractionation method has been developed which allows the generation of highquality samples from natural origin, fulfilling the requirements of an integration into high-throughput screening programs.


2002 ◽  
Vol 30 (4) ◽  
pp. 794-797 ◽  
Author(s):  
S. Wilson ◽  
S. Howell

The diagnostics industry is constantly under pressure to bring innovation quicker to market and so the impetus to speed up product-development cycle times becomes greater. There are a number of steps in the product-development cycle where the application of high-throughput screening can help. In the case of lateral-flow immunodiagnostics the selection of antibody reagents is paramount. In particular, rapid identification of antibody pairs that are able to ‘sandwich’ around the target antigen is required. One screen that has been applied successfully is the use of surface plasmon resonance biosensors like Biacore®. Using such a system one can evaluate over 400 antibody pairings in under 5 days. Conventional approaches to screen this number of antibody pairs would take many months. Other automated screening systems like DELFIA® can be used in processing the vast amount of tests required for clinical trials. In addition, the use of robotics to automate routine product testing can be used to shorten the product-development cycle.


2018 ◽  
Vol 84 (16) ◽  
Author(s):  
Wei Zhou ◽  
Rui Huang ◽  
Zhiguang Zhu ◽  
Yi-Heng P. Job Zhang

ABSTRACT Thermostability and specific activity of enzymes are two of the most important properties for industrial biocatalysts. Here, we developed a petri dish-based double-layer high-throughput screening (HTS) strategy for rapid identification of desired mutants of polyphosphate glucokinase (PPGK) from a thermophilic actinobacterium, Thermobifida fusca YX, with both enhanced thermostability and activity. Escherichia coli colonies representing a PPGK mutant library were grown on the first-layer Phytagel-based plates, which can remain solid for 1 h, even at heat treatment temperatures of more than 100°C. The second layer that was poured on the first layer contained agarose, substrates, glucose 6-phosphate dehydrogenase (G6PDH), the redox dye tetranitroblue tetrazolium (TNBT), and phenazine methosulfate. G6PDH was able to oxidize the product from the PPGK-catalyzed reaction and generate NADH, which can be easily examined by a TNBT-based colorimetric assay. The best mutant obtained after four rounds of directed evolution had a 7,200-fold longer half-life at 55°C, 19.8°C higher midpoint of unfolding temperature (Tm), and a nearly 3-fold enhancement in specific activities compared to those of the wild-type PPGK. The best mutant was used to produce 9.98 g/liter myo-inositol from 10 g/liter glucose, with a theoretical yield of 99.8%, along with two other hyperthermophilic enzymes at 70°C. This PPGK mutant featuring both great thermostability and high activity would be useful for ATP-free production of glucose 6-phosphate or its derived products.IMPORTANCE Polyphosphate glucokinase (PPGK) is an enzyme that transfers a terminal phosphate group from polyphosphate to glucose, producing glucose 6-phosphate. A petri dish-based double-layer high-throughput screening strategy was developed by using ultrathermostable Phytagel as the first layer instead of agar or agarose, followed by a redox dye-based assay for rapid identification of ultrathermostable PPGK mutants. The best mutant featuring both great thermostability and high activity could produce glucose 6-phosphate from glucose and polyphosphate without in vitro ATP regeneration.


2018 ◽  
Vol 23 (7) ◽  
pp. 697-707 ◽  
Author(s):  
John Joslin ◽  
James Gilligan ◽  
Paul Anderson ◽  
Catherine Garcia ◽  
Orzala Sharif ◽  
...  

The goal of high-throughput screening is to enable screening of compound libraries in an automated manner to identify quality starting points for optimization. This often involves screening a large diversity of compounds in an assay that preserves a connection to the disease pathology. Phenotypic screening is a powerful tool for drug identification, in that assays can be run without prior understanding of the target and with primary cells that closely mimic the therapeutic setting. Advanced automation and high-content imaging have enabled many complex assays, but these are still relatively slow and low throughput. To address this limitation, we have developed an automated workflow that is dedicated to processing complex phenotypic assays for flow cytometry. The system can achieve a throughput of 50,000 wells per day, resulting in a fully automated platform that enables robust phenotypic drug discovery. Over the past 5 years, this screening system has been used for a variety of drug discovery programs, across many disease areas, with many molecules advancing quickly into preclinical development and into the clinic. This report will highlight a diversity of approaches that automated flow cytometry has enabled for phenotypic drug discovery.


1998 ◽  
Vol 3 (1) ◽  
pp. 13-17 ◽  
Author(s):  
John Major

In response to mounting competitive pressures, the current trend in the pharmaceutical industry is to shorten the time scale for all aspects of drug discovery. While advances in computation, structural chemistry, and molecular modeling are facilitating rational design activities, empirical screening continues to play a crucial role in lead identification. Because the ability to test large numbers of compounds quickly and efficiently can provide a competitive advantage, high throughput screening (HTS) has become a key tool in many companies. To achieve the necessary productivity, effective integration of compound supply, assay operation and data management is essential. HTS is a very high technology enterprise that must take full advantage of the latest advances in bioscience, biotechnology, engineering, and information science. There is a constant dilemma, however, in relation to when well-established, mature technologies should be replaced by new methods that promise to deliver spectacular advantages. The final decision must be based on weighing the promised benefit against the cost and risk. While huge challenges face the pharmaceutical industry, there are also opportunities for those companies that can identify and implement new technology effectively.


2011 ◽  
Vol 16 (9) ◽  
pp. 1007-1017 ◽  
Author(s):  
Joost C. M. Uitdehaag ◽  
Cecile M. Sünnen ◽  
Antoon M. van Doornmalen ◽  
Nikki de Rouw ◽  
Arthur Oubrie ◽  
...  

Over the past years, improvements in high-throughput screening (HTS) technology and compound libraries have resulted in a dramatic increase in the amounts of good-quality screening hits, and there is a growing need for follow-on hit profiling assays with medium throughput to further triage hits. Here the authors present such assays for the colony-stimulating factor 1 receptor (CSF1R, Fms), including tests for cellular activity and a homogeneous assay to measure affinity for inactive CSF1R. They also present a high-throughput assay to measure target residence time, which is based on competitive binding kinetics. To better fit koff rates, they present a modified mathematical model for competitive kinetics. In all assays, they profiled eight reference inhibitors (imatinib, sorafenib, sunitinib, tandutinib, dasatinib, GW2580, Ki20227, and J&J’s pyrido[2,3-d]pyrimidin-5-one). Using the known biochemical selectivities of these inhibitors, which can be quantified using metrics such as the selectivity entropy, the authors have determined which assay readout best predicts hit selectivity. Their profiling shows surprisingly that imatinib has a preference for the active form of CSF1R and that Ki20227 has an unusually slow target dissociation rate. This confirms that follow-on hit profiling is essential to ensure that the best hits are selected for lead optimization.


2001 ◽  
Vol 6 (6) ◽  
pp. 429-440 ◽  
Author(s):  
Michael W. Pantoliano ◽  
Eugene C. Petrella ◽  
Joseph D. Kwasnoski ◽  
Victor S. Lobanov ◽  
James Myslik ◽  
...  

More general and universally applicable drug discovery assay technologies are needed in order to keep pace with the recent advances in combinatorial chemistry and genomics-based target generation. Ligand-induced conformational stabilization of proteins is a well-understood phenomenon in which substrates, inhibitors, cofactors, and even other proteins provide enhanced stability to proteins on binding. This phenomenon is based on the energetic coupling of the ligand-binding and protein-melting reactions. In an attempt to harness these biophysical properties for drug discovery, fully automated instrumentation was designed and implemented to perform miniaturized fluorescence-based thermal shift assays in a microplate format for the high throughput screening of compound libraries. Validation of this process and instrumentation was achieved by investigating ligand binding to more than 100 protein targets. The general applicability of the thermal shift screening strategy was found to be an important advantage because it circumvents the need to design and retool new assays with each new therapeutic target. Moreover, the miniaturized thermal shift assay methodology does not require any prior knowledge of a therapeutic target's function, making it ideally suited for the quantitative high throughput drug screening and evaluation of targets derived from genomics.


2005 ◽  
Vol 10 (4) ◽  
pp. 374-382 ◽  
Author(s):  
Susan M. Young ◽  
Cristian Bologa ◽  
Eric R. Prossnitz ◽  
Tudor I. Oprea ◽  
Larry A. Sklar ◽  
...  

High-throughput flow cytometry (HTFC), enabled by faster automated sample processing, represents a promising high- content approach for compound library screening. HyperCyt® is a recently developed automated HTFC analysis system by which cell samples are rapidly aspirated from microplate wells and delivered to the flow cytometer. The formylpeptide receptor (FPR) family of G protein–coupled receptors contributes to the localization and activation of tissue-damaging leukocytes at sites of chronic inflammation. Here, the authors describe development and application of an HTFC screening approach to detect potential anti-inflammatory compounds that block ligand binding to FPR. Using a homogeneous no-wash assay, samples were routinely processed at 1.5 s/well (~2500 cells analyzed/sample), allowing a 96-well plate to be processed in less than 2.5 min. Assay sensitivity and accuracy were validated by detection of a previously documented active compound with relatively low FPR affinity (sulfinpyrazone, inhibition constant [Ki]=14 μM) from among a collection of 880 compounds in the Prestwick Chemical Library. The HyperCyt® system was therefore demonstrated to be a robust, sensitive, and highly quantitative method with which to screen lead compound libraries in a 96-well format.


2006 ◽  
Vol 11 (5) ◽  
pp. 481-487 ◽  
Author(s):  
Philip E. Brandish ◽  
Chi-Sung Chiu ◽  
Jonathan Schneeweis ◽  
Nicholas J. Brandon ◽  
Clare L. Leech ◽  
...  

Enzymes are often considered less “druggable” targets than ligand-regulated proteins such as G-protein-coupled receptors, ion channels, or other hormone receptors. Reasons for this include cellular location (intracellular vs. cell surface), typically lower affinities for the binding of small molecules compared to ligand-specific receptors, and binding (catalytic) sites that are often charged or highly polar. A practical drawback to the discovery of compounds targeting enzymes is that screening of compound libraries is typically carried out in cell-free activity assays using purified protein in an inherently artificial environment. Cell-based assays, although often arduous to design for enzyme targets, are the preferred discovery tool for the screening of large compound libraries. The authors have recently described a novel cell-based approach to screening for inhibitors of a phosphatase enzyme and now report on the development and implementation of a homogeneous 3456-well plate assay for D-amino acid oxidase (DAO). Human DAO was stably expressed in Chinese hamster ovary (CHO) cells, and its activity was measured as the amount of hydrogen peroxide detected in the growth medium following feeding the cells with D-serine. In less than 12 weeks, the authors proved the concept in 96-and then 384-well formats, miniaturized the assay to the 3456-well (nanoplate) scale, and screened a library containing more than 1 million compounds. They have identified several cell-permeable inhibitors of DAO from this cell-based high-throughput screening, which provided the discovery program with a few novel and attractive lead structures.


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