Combinatorial Chemistry & High Throughput Screening - Volume 8, Issue 4, 2005

G protein-coupled receptors (GPCRs) represent the largest super family of all receptor types, and account for the major proportion of current drug targets. Many pharmaceutical industries have embarked on high-throughput screening to identify new low molecular weight modulators for GPCRs. Many assay strategies for identification of hits from screening are available. These include assays that address the affinity of compound Read More

Cell-based assays have always played an important role in the pharmaceutical industry, providing information about the functional effects of compounds. These functional assays have traditionally accompanied facile biochemical high throughput screening programmes, being applied as secondary assays in the later stages of lead development. However, with the disappointing reality that there is not likely to be a plethora Read More

Advances in high throughput screening technologies have led to the identification of many small molecules, “hits”, with activities toward the target of interest. And, as the screening technologies become faster and more robust, the rate at which the molecules are identified continues to increase. This evolution of high throughput screening technologies has generated a significant strain on the laboratories involved with th Read More

G protein-coupled receptors (GPCRs) have been one of the most productive classes of drug targets for several decades, and new technologies for GPCR-based discovery promise to keep this field active for years to come. While molecular screens for GPCR receptor agonist- and antagonist-based drugs will continue to be valuable discovery tools, the most exciting developments in the field involve cell-based assays for GPCR f Read More

Screening technologies for G protein-coupled receptors comprise two major approaches; homogeneous assays, conducted in microtiter plate formats, and protein redistribution assays that require imaged-based analysis using automated confocal systems. Generally, the former are used in primary screening campaigns for lead identification, while the latter are used in secondary screens for lead optimization. Homogeneous Read More

IMAP® is a fluorescence polarisation-based assay method which can be applied to the measurement of protein kinase activity. Using a model serine/threonine kinase we found that IMAP generated a good assay window (Z' > 0.8), was very tolerant of DMSO, and was flexible with respect to sample processing (stopped reactions were stable over a period of several days). Using a set of six low molecular weight inhibitors of th Read More

We report a systematic analysis of the P1' and P2' substrate specificity of TNF-α converting enzyme (TACE) using a peptide library and a novel analytical method, and we use the substrate specificity information to design novel reverse hydroxamate inhibitors. Initial truncation studies, using the amino acid sequence around the cleavage site in precursor-TNF-α, showed that good turnover was obtained with the peptide DNPLA Read More

Recent studies have suggested that both constitutive androstane receptor (CAR) and pregnane Xreceptor (PXR) are involved in the induction of rat liver microsomal cytochrome P-450 (CYP) 2B and 3A through a mechanism called cross-talk. In this study we intend to determine if a PXR-reporter gene assay could be used for the prediction of CYP3A and/or CYP2B induction in rats. The induction of rat CYP2B and CYP3A by nineteen Read More

Metalloporphyrin catalyzed biomimetic oxidation was used for the identification of nitric oxide (NO) donors with diverse chemical structure. Methodology was validated by testing known NO donors. Efficient automation of the test allowed us to investigate a subset of our corporate library. Several hits identified in this campaign were validated in both the chemical and also microsomal model that revealed all hits to be active Read More

The increasing no. of ordered coagulation screening tests has led to a remarkable improvement in the efficiency of automated coagulation testing, and appearance of a new generation of high throughput analyzers ensuring accuracy and precision, and reducing the strain and human error. The earliest analyzers operated mechanically, using the hook to detect the clot in the cuvette are now replaced with more sophisticated anal Read More

The area of solid-phase synthesis has witnessed exponential growth in the last fifteen years, but difficulties associated with the monitoring and analysis of resin-bound reactions and products have been apparent due to a limited number of analytical methods available. With the substrate tethered to an insoluble support traditional chromatographic monitoring is only possible after cleavage. In order to address this 'analytic Read More

Dr. Guido Zaman is Section Head Molecular in the Pharmacology Unit of N.V. Organon in Oss, the Netherlands. His section is responsible for assay development from cDNA to HTS, and in vitro biological testing from hit to clinical candidate. Guido completed his PhD in molecular biology on protein - RNA interaction at the University of Nijmegen in 1991, and studied multidrug resistance of human cancer cells at the Netherlan Read More