CellAura products are now part of the Hello Bio range
Fri 1 Jul 2016
Hello Bio is a leading supplier of high quality, low-cost life science tools, including agonists, antagonists, inhibitors, signaling and fluorescent tools. CellAura products are now part of the Hello Bio range, and can be ordered directly from Hello Bio.
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CellAura Workshop Synopsis
Thu 17 May 2012
The CellAura Technologies workshop on fluorescence approaches for examining GPCR biology, held on 25th April 2012, was a resounding success. Considerable interest was generated by the speaker presentations which showcased several ground-breaking applications. There were lively lunchtime round-table discussions, and several new projects and collaborations arose as a consequence. A number of delegates also took up the offer of free ligand samples from CellAura to test as a demonstration on a PHERAstar FS plate-reader provided by BMG Labtech.
A synopsis of the speaker presentations is given below:
Leigh Stoddart (University of Nottingham) described a High Content Analysis approach for fragment library screening in live cells. The assay used CellAura’s fluorescent adenosine receptor ligand (CA200645) in live-cell imaging of adenosine A3 receptors, using the Molecular Devices Image Xpress Ultra and a small fragment library (compounds < 250 MWt) was screened for novel ligands. Hits with affinities < 1µM were readily detected, and could be resolved into agonists (inducing YFP-tagged receptor internalisation) or antagonists (no internalisation).
· This approach provides an important, live cell alternative to biophysical techniques applied to purified receptor protein for fragment library screening at GPCRs.
Lauren May (Monash University, Australia) presented another alternative to biophysical techniques to measure the kinetics of ligand binding to GPCRs in live cells under normal physiological conditions. Using a cell culture perfusion system mounted on a confocal fluorescence microscope, a fluorescent adenosine receptor agonist (similar to CA200623) was perfused across cells expressing adenosine A3 receptors. The membrane fluorescence of single, individual cells was quantified over time, to give ligand binding association curves. Washing off the fluorescent ligand under continuous flow then generated ligand dissociation curves. However, adding unlabelled compounds to the wash buffer modified the dissociation rate – an interaction that demonstrates the allosteric effect of the unlabelled compound to change the affinity of the receptor for the fluorescent ligand. Using a split YFP bimolecular complementation effect between co-expressed GFP- and RFP-tagged A3 receptors, Lauren demonstrated that the A3 receptors exist as a homodimers and that allosteric modulators act on one partner in the homodimer to affect the ligand affinity of the other.
· This assay provides an important physiological approach for identifying positive and negative allosteric modulators (PAMs and NAMs) as novel drug candidates.
Andrew Ede (eg technology, Cambridge) reported on progress to develop an automated version of the perfusion system used by Lauren, as a commercially available instrument. The system comprises two elements: 1) a temperature controlled cell culture perfusion chamber in a universal plate format holder for mounting onto a variety of confocal microscopes, and 2) the components for buffer and sample temperature control, sample handling, and buffer or sample perfusion,
· Beta systems will be trialled with selected partners during 2012, with the first commercial units available early in 2013.
Sergei Kopanchuk (University of Turku, Estonia) described the use of 1-, 2- and 3-photon fluorescence anisotropy for measuring the dynamics of fluorescent ligand binding to GPCRs. Using high affinity fluorescent peptide ligands for the melanocortin 4 (MC4) receptor, the fluorescence intensity of bound ligand was quantified. The binding data best fitted a 2-state binding model, in which binding to a second site was dependent on a first site already being bound. These data confirmed that MC4 receptors also exist and function as homodimers.
· Fluorescence anisotropy provides a robust alternative to fluorescence polarisation (FP) for measuring fluorescent ligand binding, but only requires a single orthogonally-oriented photo-detector.
Steve Briddon (University of Nottingham) presented the work of Ross Corriden to visualise and localise the binding of a CellAura fluorescent adenosine ligand (CA200645) to endogenous adenosine A1 and A3 receptors in human neutrophils using real-time confocal microscopy. Receptors were found to be clustered in ‘plaques’ located at the leading edge of neutrophils as they advanced towards chemo-attractant stimuli, and at the bases of 50 – 100µm nanotube extensions, protruding from the leading edge. This allows the neutrophils to locate and contact bacteria before drawing them in for engulfment.
· Resolving the biological processes underlying endogenous GPCR function leading to neutrophil chemotaxis and engulfment has only been possible using fluorescent ligands and confocal microscopy.
Catherine Wark (BMG Labtech, Aylesbury) described the performance features of the PHERAstar FS that make it a superior top or bottom read multi-modal fluorescence scanning plate-reader, ideal for quantifying fluorescent ligands binding to cells grown on the bottom surface of multi-well plates. Maria Arruda (Farmanguinhos, Fiocruz, Brazil and University of Nottingham) then recapitulated the High Content Analysis assay format presented by Leigh Stoddart, going on to describe identical studies quantified much more rapidly using the PHERAstar FS.
· Using fluorescent ligands to perform live cell binding assays, combined with the high performance characteristics of the PHERAstar FS therefore provides a viable alternative to radioligand binding for studying receptor pharmacology and for high throughput screening.
Michelle Bradley (Novartis, Horsham) described the pharmacology of indacaterol, a long acting beta2 adrenoceptor agonist for the treatment of COPD. Novartis required a fluorescent derivative of indacaterol to investigate ligand and receptor trafficking as part of studies to understand its mode of action. CellAura provided a custom ligand development service, as described by Richard Middleton (CellAura, Nottingham). The ligand design and synthesis campaign was outlined, leading to a set of 10 ligands for testing. One fluorescent indacaterol derivative closely approached the pharmacology of the parent (similar affinity, similar partial agonist activity), but was slightly too lipophilic. A second iteration generated two further ligands, one of which was selected by Novartis for further study. Michelle then described studies performed in bronchial smooth muscle cells expressing GFP-tagged beta2 adrenoceptors and the fluorescent indacaterol ligand, where receptor (green) and ligand (red) were seen to be co-localised and internalised. Adding unlabelled antagonists blocked the receptor internalisation demonstrating a predictable pharmacological profile.
· CellAura is able to create tailored, custom fluorescent ligands that replicate both the pharmacological properties of the unlabelled parent AND the physicochemical requirements, to deliver fluorescent ligands that had been shown to work in a wide variety of assays.
CellAura Workshop Programme
Fri 10 Feb 2012
The Programme for the CellAura User Group Workshop to be held at BioCity on 25th April 2012 is as follows:
|Arrival, Registration and Coffee
|Welcome and Introduction
||Professor Steve Hill
||University of Nottingham, UK
High content and fragment screening of
GPCRs in living cells
|Dr Leigh Stoddart
||University of Nottingham, UK
Single cell kinetic analysis of ligand binding:
impact of dimerisation and allosterism
|Dr Lauren May
||Monash University, Australia
Fluorescence anisotropy for ligand binding
dynamics to GPCRs
|Dr Sergei Kopanchuk
||University of Tartu, Estonia
Lunch, Networking and Demonstrations
Measurement of ligand binding to
endogenous GPCRs in human neutrophils
|Dr Steve Briddon
||University of Nottiingham, UK
Measurement of the binding of fluorescent
ligands to GPCRs using the BMG PharaStar FS
Dr Catherine Wark
Dr Maria Arruda
BMG Labtech, UK
Farmanguinhos, Fiocruz, Brazil
Fluorescent ligand approaches - an industry
Dr Michelle Bradley
Dr Richard Middleton
Novartis, Horsham, UK
CellAura, Nottingham, UK
Summary and Close
|Professor Steve Hill
||University of Nottingham, UK
Transport arrangements provided by CellAura Technologies before and after the meeting will be announced on the CellAura News page in due course.
To register your interest in attending the meeting and to receive a Delegate Pack, please call CellAura Technologies on: +44 (0)115 912 4415, or e-mail: firstname.lastname@example.org, or visit the CellAura Events page on LinkedIn.
CellAura User Group Workshop
Mon 9 Jan 2012
CellAura Technologies invites its customers, current users of fluorescent ligands, and those interesting in learning more about the uses of fluorescent ligands, to attend the Inaugural Fluorescent Ligands Workshop to be held at BioCity on 25th April 2012.
The meeting will be Chaired by Professor Steve Hill from the University of Nottingham.
The provisional speaker line-up includes:
Dr Leigh Stoddart (University of Nottingham, UK)
Dr Lauren May (Monash University, Australia)
Dr Sergei Kopanchuk (University of Tartu, Estonia)
Dr Steve Briddon (University of Nottingham, UK)
Dr Catherine Wark (BMG Labtech, UK) & Dr Maria Arruda (Farmanguinhos, Fiocruz, Brazil)
Dr Michelle Bradley (Novartis, Horsham, UK) & Dr Richard Middleton (CellAura, UK)
There will also be selected assay and instrument demonstrations running during the Workshop.
Transport between the BPS venue in Leicester and BioCity for the workshop will be provided by CellAura.
Information about registering for the Workshop is provided on the CellAura Events
Further news about the Speaker presentations and Workshop demonstrations will be posted in due course on the CellAura News
page and via the CellAura Events
page on LinkedIn.
CellAura launches Fluorescent Ligands discussion group on LinkedIn
Fri 18 Nov 2011
CellAura has launched a discussion group on LinkedIn titled: Fluorescent Ligands - enabling novel GPCR Biology and Drug Discovery.
The purpose of the group is to provide a forum for discussions promoting the novel thinking that is emerging around the use of fluorescent GPCR ligands for research and drug discovery.
The group is an exclusive members-only global scientific forum for professionals from Pharma, Biotech and Academia.
If you would like to join the forum, please use your LinkedIn profile to send us a request to join.
CellAura launches new beta3 adrenoceptor agonist fluorescent ligand
Wed 1 Jun 2011
CellAura has added a new fluorescent adrenoceptor ligand to its product catalogue.
The new fluorescent ligand has been developed for the beta-adrenoceptor family based on the beta-blocker, carazolol. The new fluorescent (S)-carazolol-derivative is a partial agonist at β3 adrenoceptors, and acts as an antagonist at β1 and β2 adrenoceptors The new product is now available as a standard catalogue item.
Further product development is expected to include new serotonergic receptor ligands and to provide full coverage of the muscarinic receptor family. These additional products will be launched over the forthcoming months.
CellAura to showcase Fluorescent Ligand Perfusion Technology design concept at ELRIG Cell-Based Screening meeting
Fri 25 Feb 2011
The ELRIG Advances in Cell Based Screening Technologies meeting at Hinxton Hall, Cambridge, UK, on 15th March 2011, is a free-to-register event that will present the latest cutting edge detection technologies and biological techniques transitioning into screening labs.
CellAura Technologies will be attending the ELRIG Cell Based Screening meeting to promote its expanding range of fluorescent GPCR ligands for drug discovery and life science research. It will also be show-casing its design concept for a Confocal Perfusion System to be mounted onto a range of confocal microscope platforms. Please register for the meeting (click here) and visit our booth to discuss your interest in our reagents and perfusion technology.
CellAura signs license with University of Nottingham to access Confocal Perfusion System for measuring fluorescent ligand binding kinetics
Tue 4 Jan 2011
The University of Nottingham has developed a novel perfusion system mounted onto a confocal fluorescence microscope that allows the binding of fluorescent ligands to GPCRs expressed on live cells to be observed in real-time. Quantification of ligand binding and dissociation from individual cells under continuous perfusion flow allows the kinetics of ligand-receptor interactions to be determined. This is probably the first technology to be able to determine ligand binding kinetics on a single live cell.
CellAura has signed a license with the University of Nottingham to be able to access the novel perfusion system, which uses CellAura’s fluorescent ligands as its principal reagent. It is CellAura’s intention to commercialise the perfusion technology to provide an instrument platform on which its reagents can be readily used to measure ligand affinity, binding duration, and allosteric effects of drug candidates to alter fluorescent ligand binding and dissociation rates.