We all see, feel, experience and interpret the world around us differently; you could say we each have a unique perspective. This is partly based on environmental factors that have preconditioned our reaction and response to different stimuli or situations, and partly based on the genes we inherited from our parents, and they from theirs and so on. But when we can really see something for what it is, the hard facts are impossible to ignore and a confident unanimous interpretation is almost guaranteed.
Opinions have consequences…
In an analytical sense, we interpret and draw conclusions based on what we see in our data, which is often generated using a multitude of techniques. In the bio/pharmaceutical industry, the interpretation of analytical data directly impacts the development of candidate therapeutics, and in turn, affects the fate of those awaiting the next ground-breaking therapy. It is, therefore, paramount that a full picture of any new/prospective active pharmaceutical ingredient (API) is obtained in order to understand its potential safety (toxicity) and effectiveness for the intended indication.
Gaining a full and true picture of any molecule, in particular one which is biologically produced/biological in nature, is far from simple -- even with advanced chromatographic and spectroscopic techniques, using just one method (or taking one perspective) rarely provides full structural insights into complex, 3-dimensional macromolecules, such as proteins. Take a typical monoclonal antibody (mAb) biotherapeutic, for example. There are multiple layers of structural complexity, numerous possible structural variants, thousands of possible post-translational modifications (PTMs), charge variants and impurities (host cell proteins, extractables and leachables)from production. All of these could, if not detected, removed, monitored and controlled, make their way into the final drug product and impact patient safety.
For this reason, the characterization of mAbs involves an analytical toolbox of workflows which include, but are not limited to, liquid chromatography (LC), mass spectrometry (MS) and many (often complex) sample preparation techniques and software packages to aid in data interpretation. Each workflow offers a perspective view of the mAb, and the summation of numerous workflows, or perspectives, illuminates any new or unexpected features.
Developments in modern mass spectrometers have allowed researchers in the bio/pharmaceutical industry to embrace a technique which has typically been confined to academic barracks -- native MS (see my previous blog post on flying elephants). Native MS is unique in the fact that it allows the structural integrity of a molecule to be maintained, as it would be in a biological matrix, in the mass spectrometer. This provides analysts with a whole new perspective on their drug’s structure, compared with other (denaturing) MS approaches and/or LC-based workflows.
Earlier this year I met with a team of esteemed native MS scientists at a new contract research organisation (CRO) based in Oxford in the UK. They go by the name of ‘OMass’ or Oxford Mass Technologies, and are the brainchild of the world-renowned protein analyst Prof. Dame Carol Robinson. It’s fair to say I was star-struck in the presence of such immense sci-girl-power (no biggie, she was only the first female Professor of Chemistry at the University of Oxford, was previously the first female Professor of Chemistry at the University of Cambridge, is currently Royal Society Research Professor, Doctor Lee’s Professor at the University of Oxford and a Dame Commander of the Order of the British Empire!), but once I got over the initial shock I was amazed to hear the story behind the company and the range of new and bespoke services they had on offer, including intact biotherapeutic characterization (including biosimilars, bispecifics and antibody-drug conjugates (ADCs)), drug binding studies, membrane protein analysis and protein purification analysis. The wider OMass team all (unsurprisingly) share their origins in native MS-focused academic research and they display an intense passion for the development and provision of native MS as an accessible, routine tool for structural biology.
Their specialism lies in applying MS to the characterisation of intact protein assemblies. By preserving the structures of protein assemblies, they are able to provide structural insights into large, dynamic complexes. OMass uses the latest MS instrumentation, including the Thermo Scientific™ Q Exactive Plus™ (Ultra High Mass Range) hybrid quadrupole-Orbitrap MS. Cumulatively, more than 30 years of academic research in the field of native MS led to the creation of this modified, fine-tuned system to capture, transmit and detect intact proteins and generate unsurpassed high resolution data and structural insights.
In the ultra high mass range Q Exactive, non-covalent interactions between protein subunits and small molecules can be preserved and observed directly, providing an exciting opportunity to visualise relatively tiny drug molecules binding to macromolecular assemblies, or to observe and characterise the various PTMs present on a protein target (such as the different glycoforms of a mAb). Breakthroughs at OMass in applying native MS to membrane proteins have expanded the capabilities of this technology to study drug targets, such as the analysis of G-protein-coupled receptors (GPCRs) and ion channels.
To learn more about the new perspective that native MS is bringing to drug discovery, and the story of OMass, make sure you check out the new video.