Label-free screening - Articles and news items

Development of biosensor assays for fragment screening of wild type GPCRs

Webinars / 14 October 2015 /

In this webinar, we discuss SPR fragment screening of wild type GPCRs enabled by sensitive biosensors and optimised membrane protein assays…

Cell based label-free assays in GPCR drug discovery

GPCRs: Cell based label-free assays in GPCR drug discovery

Drug Targets, Issue 4 2013 / 20 August 2013 / Niklas Larsson, Linda Sundström, Erik Ryberg and Lovisa Frostne (AstraZeneca)

G protein-coupled receptors are one of the major classes of therapeutic targets for a broad range of diseases. The most commonly used assays in GPCR drug discovery measure production of second messengers such as cAMP or IP3 that are the result of activation of individual signalling pathways. Such specific assays are unable to provide a holistic view of the cell response after GPCR activation. This is now changing as label-free technologies and assays on whole cells have been developed that are unbiased towards the specific downstream pathways and capture the integrated cell response. In this mini-review, we focus on the application of one of these technologies, namely resonant waveguide grating (RWG) for measurements of dynamic mass redistribution (DMR) in intact cells upon GPCR activation. Since the technology is sensitive and non-invasive, it is applicable to most cell types, including primary cells with native receptor expression levels. We discuss how DMR assays have become an important component of GPCR drug discovery screening cascades and may have the potential to improve the ability to predict if compounds will be efficacious in vivo.

Label-free quantitative proteomics: Why has it taken so long to become a mainstream approach?

Label-free quantitative proteomics: Why has it taken so long to become a mainstream approach?

Issue 3 2013, Proteomics / 13 June 2013 / Thierry Le Bihan, SynthSys and Institute of Structural and Molecular Biology, University of Edinburgh

In recent years, mass spectrometry (MS) based proteomics has moved from being a qualitative tool (used to mainly identify proteins) to a more reliable analysis tool, allowing relative quantitation as well as absolute quantitation of a large number of proteins. However, the developed quantitative methods are either specific for certain types of samples or certain types of mass spectrometers. In some cases, developing expertise on how to use a given method may take a long time and the use of these methods is therefore limited to few laboratories. Other quantitative methods are suitable for simple standard protein mixes which are far from the complexity of real samples. As a consequence, the number of available quantitative methods is high and choosing the right one is challenging.

What is label-free screening and why use it in drug discovery?

What is label-free screening and why use it in drug discovery?

Issue 6 2012, Screening / 18 December 2012 / Matthew A. Cooper and Reena Halai, Institute for Molecular Bioscience, the University of Queensland

In the journey of a molecule from its origins in a compound library to candidate drug status, a large variety of profiling must occur to define activity, selectivity, potency, adverse effects, pharmacology and in vivo efficacy. Advances in biophysical methods that can analyse drug interactions with a molecular target, a whole cell, or even ex vivo tissue have enabled many of these studies to be carried out without the need for reporter-based or ‘labelled’ assays. Label-free screening in high-throughput mode can be used as a pathway independent screening tool with whole cells, or in low-throughput mode with individual receptors to define interaction kinetics and thermodynamics. We highlight advances in optical and impedance-based biosensors, and examine their utility and suitability for various stages of the drug discovery process.

In the early to mid 20th century, drug discovery was a far more productive industry, and more drugs were launched per Pharma employee than today. The regulatory pathway that pre-empted the launch of a new drug was concise and easy to understand, and applications were dealt with expeditiously with a fraction of the supporting data required today. The process of discovery was also very different; it was driven largely by individuals in small teams who were prepared for serendipity, or by individuals with a very clear, defined hypothesis who drove rational drug design. Screening technologies could be summed up on one or two pages of a review; a dozen or so primary assays, some basic biochemistry to define ligand mode of action, perhaps some live cell work and a proof of concept demonstration in vivo…


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