A framework for the rational selection of a minimal suite of nondegenerate developability assays (DAs) that maximize insight into candidate developability or storage stability is lacking. To address this, we subjected nine formulation:mAbs to 12 mechanistically distinct DAs together with measurement of their accelerated and long-term storage stability. We show that it is possible to identify a reduced set of key variables from this suite of DAs by using orthogonal statistical methods.
View Article and Find Full Text PDFGreat progress has been made in the detection of large biomolecular analytes by native mass spectrometry; however, characterizing highly heterogeneous samples remains challenging due to the presence of many overlapping signals from complex ion distributions. Electron-capture charge reduction (ECCR), in which a protein cation captures free electrons without apparent dissociation, can separate overlapping signals by shifting the ions to lower charge states. The concomitant shift to higher / also facilitates the exploration of instrument upper / limits if large complexes are used.
View Article and Find Full Text PDFNative mass spectrometry is a potent method for characterizing biomacromolecular assemblies. A critical aspect to extracting accurate mass information is the correct inference of the ion ensemble charge states. While a variety of experimental strategies and algorithms have been developed to facilitate this, virtually all approaches rely on the implicit assumption that any peaks in a native mass spectrum can be directly attributed to an underlying charge state distribution.
View Article and Find Full Text PDFCell line development is an essential stage in biopharmaceutical development that often lies on the critical path. Failure to fully characterise the lead clone during initial screening can lead to lengthy project delays during scale-up, which can potentially compromise commercial manufacturing success. In this study, we propose a novel cell line development methodology, referenced as , which involves four steps enabling autonomous data-driven selection of the lead clone.
View Article and Find Full Text PDFAntibody drug conjugates, a class of biotherapeutic proteins, have been extensively developed in recent years, resulting in new approvals and improved standard of care for cancer patients. Among the numerous strategies of conjugating cytotoxic payloads to monoclonal antibodies, insertion of a cysteine residue achieves a tightly controlled, site-specific drug to antibody ratio. Tailored analytical tools are required to direct the development of processes capable of manufacturing novel antibody scaffolds with the desired product quality.
View Article and Find Full Text PDFAllostery is a fundamental mechanism of protein activation, yet the precise dynamic changes that underlie functional regulation of allosteric enzymes, such as glycogen phosphorylase (GlyP), remain poorly understood. Despite being the first allosteric enzyme described, its structural regulation is still a challenging problem: the key regulatory loops of the GlyP active site (250' and 280s) are weakly stable and often missing density or have large b-factors in structural models. This led to the longstanding hypothesis that GlyP regulation is achieved through gating of the active site by (dis)order transitions, as first proposed by Barford and Johnson.
View Article and Find Full Text PDFAmide hydrogen/deuterium-exchange mass spectrometry (HDX-MS) is a powerful tool for analyzing the conformational dynamics of proteins in a solution. Current conventional methods have a measurement limit starting from several seconds and are solely reliant on the speed of manual pipetting or a liquid handling robot. Weakly protected regions of polypeptides, such as in short peptides, exposed loops and intrinsically disordered the protein exchange on the millisecond timescale.
View Article and Find Full Text PDFAntibody-drug conjugates (ADCs) are valuable therapeutic entities which leverage the specificity of antibodies to selectively deliver cytotoxins to antigen-expressing targets such as cancer cells. However, current methods for their construction still suffer from a number of shortcomings. For instance, using a single modification technology to modulate the drug-to-antibody ratio (DAR) in integer increments while maintaining homogeneity and stability remains exceptionally challenging.
View Article and Find Full Text PDFAlthough monoclonal antibodies have greatly improved cancer therapy, they can trigger side effects due to on-target, off-tumor toxicity. Over the past decade, strategies have emerged to successfully mask the antigen-binding site of antibodies, such that they are only activated at the relevant site, for example, after proteolytic cleavage. However, the methods for designing an ideal affinity-based mask and what parameters are important are not yet well understood.
View Article and Find Full Text PDFNext generation modified antisense oligonucleotides (ASOs) are commercially approved new therapeutic modalities, yet poor productive uptake and endosomal entrapment in tumour cells limit their broad application. Here we compare intracellular traffic of anti KRAS antisense oligonucleotide (AZD4785) in tumour cell lines PC9 and LK2, with good and poor productive uptake, respectively. We find that the majority of AZD4785 is rapidly delivered to CD63+late endosomes (LE) in both cell lines.
View Article and Find Full Text PDFAntibody-drug conjugates have become one of the most actively developed classes of drugs in recent years. Their great potential comes from combining the strengths of large and small molecule therapeutics: the exquisite specificity of antibodies and the highly potent nature of cytotoxic compounds. More recently, the approach of engineering antibody-drug conjugate scaffolds to achieve highly controlled drug to antibody ratios has focused on substituting or inserting cysteines to facilitate site-specific conjugation.
View Article and Find Full Text PDFIEEE Trans Vis Comput Graph
September 2022
The dominant markup language for Web visualizations-Scalable Vector Graphics (SVG)-is comparatively easy to learn, and is open, accessible, customizable via CSS, and searchable via the DOM, with easy interaction handling and debugging. Because these attributes allow visualization creators to focus on design on implementation details, tools built on top of SVG, such as D3.js, are essential to the visualization community.
View Article and Find Full Text PDFNMR studies and X-ray crystallography have shown that the structures of the 99-residue amyloidogenic protein β-microglobulin (βm) and its more aggregation-prone variant, D76N, are indistinguishable, and hence, the reason for the striking difference in their aggregation propensities remains elusive. Here, we have employed two protein footprinting methods, hydrogen-deuterium exchange (HDX) and fast photochemical oxidation of proteins (FPOP), in conjunction with ion mobility-mass spectrometry, to probe the differences in conformational dynamics of the two proteins. Using HDX-MS, a clear difference in HDX protection is observed between these two proteins in the E-F loop (residues 70-77) which contains the D76N substitution, with a significantly higher deuterium uptake being observed in the variant protein.
View Article and Find Full Text PDFProtein biopharmaceuticals are highly successful, but their utility is compromised by their propensity to aggregate during manufacture and storage. As aggregation can be triggered by non-native states, whose population is not necessarily related to thermodynamic stability, prediction of poorly-behaving biologics is difficult, and searching for sequences with desired properties is labour-intensive and time-consuming. Here we show that an assay in the periplasm of E.
View Article and Find Full Text PDFClimate change is likely to change the relationships between commonly used climate indices and underlying patterns of climate variability, but this complexity is rarely considered in studies using climate indices. Here, we show that the physical and ecological conditions mapping onto the Pacific Decadal Oscillation (PDO) index and North Pacific Gyre Oscillation (NPGO) index have changed over multidecadal timescales. These changes apparently began around a 1988/1989 North Pacific climate shift that was marked by abrupt northeast Pacific warming, declining temporal variance in the Aleutian Low (a leading atmospheric driver of the PDO), and increasing correlation between the PDO and NPGO patterns.
View Article and Find Full Text PDFClin Child Psychol Psychiatry
October 2020
The article examines the experience of parenting a child with a diagnosis of autism with a focus on scripts and intentions in relation to the parents' own childhood experiences of being parented. Five parents participated in a multiple case study design involving in-depth interviews, Adult Attachment Interviews and a parenting intentions scaling task. The findings revealed that all of the parents had experienced significant adverse events in their own childhoods, including trauma and losses.
View Article and Find Full Text PDFDifferences in conformational dynamics between two full-length monoclonal antibodies have been probed in detail using Fast Photochemical Oxidation of Proteins (FPOP) followed by proteolysis and LC-ESI-MS/MS analyses. FPOP uses hydroxyl radical labeling to probe the surface-accessible regions of proteins and has the advantage that the resulting covalent modifications are irreversible, thus permitting optimal downstream analysis. Despite the two monoclonal antibodies (mAbs) differing by only three amino acids in the heavy chain complementarity determining regions (CDRs), one mAb, MEDI1912-WFL, has been shown to undergo reversible self-association at high concentrations and exhibited poor pharmacokinetic properties in vivo, properties which are markedly improved in the variant, MEDI1912-STT.
View Article and Find Full Text PDFAlthough climate-induced shifts in fish distribution have been widely reported at the population level, studies that account for ontogenetic shifts and subregional differences when assessing responses are rare.In this study, groundfish distributional changes in depth, latitude, and longitude were assessed at different size classes by species within nine subregions. We examined large, quality-controlled datasets of depth-stratified-random bottom trawl surveys conducted during summer in three large regions-the Gulf of Alaska and the west coasts of Canada and the United States-over the period 1996-2015, a time period punctuated by a marine "heat wave.
View Article and Find Full Text PDFType 2 diabetes (T2D) is a complex and progressive disease requiring polypharmacy to manage hyperglycaemia and cardiovascular risk factors. However, most patients do not achieve combined treatment goals. To address this therapeutic gap, we have developed MEDI4166, a novel glucagon-like peptide-1 (GLP-1) receptor agonist peptide fused to a proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralising antibody that allows for glycaemic control and low-density lipoprotein cholesterol (LDL-C) lowering in a single molecule.
View Article and Find Full Text PDFStructural variation in multicompartment micelles consisting of lipophilic-hydrophilic-fluorophilic (hereafter referred to as BAC) triblock copolymers is investigated using the dissipative particle dynamics simulation method. It is demonstrated from our results that the structure of BAC multicompartment micelles is effectively tuned as a function of the lipophilic-fluorophilic ratio parameter, here termed [Formula: see text], of the constituent linear triblock copolymers. In particular, a morphological deviation from onion-like ABC micelles arises in BAC micelle systems as [Formula: see text] increases.
View Article and Find Full Text PDFThe structural variation of multicompartment micelles is investigated using a dissipative particle dynamics simulation method for nano-reactor application. It turns out that well-defined multicompartment micelles with channel structures can be generated through the self-assembly of triblock copolymers consisting of a hydrophilic (A), a lipophilic (B), and a fluorophobic (C) block arranged in a B-A-C sequence: The corona and core are formed by the hydrophilic A block and the fluorophilic C block, respectively while the channel between the aqueous phase and core is formed by the lipophilic B block and the core. By performing a set of simulations, it is confirmed that channel size can be controlled as a function of the block length ratios between blocks A and B.
View Article and Find Full Text PDFBackground And Objective: Evaluating the time taken at each step in a patient office visit is important for physicians and clinical staff for clinic workflow improvements. Very little data exists on efficiency that is not self-reported by physicians. Employees often have perceptions of the efficiency of a clinic without supporting data.
View Article and Find Full Text PDFIn this work, we present a thorough procedure for estimating the Flory-Huggins χ-parameter for use in atomistic and mesoscale molecular simulations in computational materials science. In particular, we propose improvements upon traditional Flory-Huggins theory by implementing a Connolly volume normalization (CVN). We apply this technique to several test systems, including a blend of poly (epichlorohydrin) and poly (methyl acrylate), a blend of polyethylene glycol and poly (methyl methacrylate), a blend of polystyrene and deuterated polystyrene, and three molecular-weight variants (monomer, dimer, and trimer) of a triblock copolymer for use in multicompartment micelle applications.
View Article and Find Full Text PDFMonoclonal antibodies (mAbs) currently dominate the biopharmaceutical sector due to their potency and efficacy against a range of disease targets. These proteinaceous therapeutics are, however, susceptible to unfolding, mis-folding, and aggregation by environmental perturbations. Aggregation thus poses an enormous challenge to biopharmaceutical development, production, formulation, and storage.
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