A5070046456- Lipid Membrane Structure and Behavior
- Photoreceptor and optogenetics research
- Protein Structure and Dynamics
- RNA and protein synthesis mechanisms
- Photosynthetic Processes and Mechanisms
- Neuroscience and Neuropharmacology Research
- Drug Transport and Resistance Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Bacterial Genetics and Biotechnology
- Cellular transport and secretion
- DNA and Nucleic Acid Chemistry
- Photochemistry and Electron Transfer Studies
- Supramolecular Self-Assembly in Materials
- Enzyme Structure and Function
- Antibiotic Resistance in Bacteria
- ATP Synthase and ATPases Research
- Metabolomics and Mass Spectrometry Studies
- Force Microscopy Techniques and Applications
- Analytical Chemistry and Chromatography
- Endoplasmic Reticulum Stress and Disease
- Amino Acid Enzymes and Metabolism
- Receptor Mechanisms and Signaling
- Erythrocyte Function and Pathophysiology
- Algal biology and biofuel production
King's College London
2015-2025
Trinity House
2017-2025
The Francis Crick Institute
2022
Imperial College London
1991-2021
Molecular Sciences Institute
2021
Transnational Press London
2015-2021
King's College Hospital
2019
University of Bristol
2007-2016
King's College - North Carolina
2015
Annamalai University
2011
An ability to mimic the boundaries of biological compartments would improve our understanding self-assembly and provide routes new materials for delivery drugs biologicals development protocells. We show that short designed peptides can be combined form unilamellar spheres approximately 100 nanometers in diameter. The design comprises two, noncovalent, heterodimeric homotrimeric coiled-coil bundles. These are joined back render two complementary hubs, which when mixed hexagonal networks...
The ability to maintain interactions between soluble protein subunits in the gas phase of a mass spectrometer gives critical insight into stoichiometry and interaction networks complexes. Conversely, for membrane complexes micelles, transition usually leads disruption interactions, particularly cytoplasmic subunits, spectrum dominated by large aggregates detergent molecules. We show that applying nanoelectrospray micellar solution complex, heteromeric adenosine 5′-triphosphate (ATP)–binding...
Protein engineering, chemical biology, and synthetic biology would benefit from toolkits of peptide protein components that could be exchanged reliably between systems while maintaining their structural functional integrity. Ideally, such should highly defined predictable in all respects sequence, structure, stability, interactions, function. To establish one toolkit, here we present a basis set de novo designed α-helical coiled-coil peptides adopt well-characterized parallel dimeric,...
Abstract Secondary transporters undergo structural rearrangements to catalyze substrate translocation across the cell membrane – yet how such conformational changes happen within a lipid environment remains poorly understood. Here, we combine hydrogen-deuterium exchange mass spectrometry (HDX-MS) with molecular dynamics (MD) simulations understand lipids regulate of secondary at level. Using homologous XylE, LacY and GlpT from Escherichia coli as model systems, discover that conserved...
To date, reconstitution of one the fundamental methods cell communication, signaling pathway, has been unaddressed in bottom-up construction artificial cells (ACs). Such developments are needed to increase functionality and biomimicry ACs, accelerating their translation application biotechnology. Here, we report a de novo synthetic pathway microscale nested vesicles. Vesicle-cell models respond external calcium signals through activation an intracellular interaction between phospholipase A2...
We detail an approach for constructing asymmetric membranes and characterising their mechanical properties, leading to the first measurement of effect asymmetry on lipid bilayer mechanics.
Abstract The interplay between membrane proteins and the lipids of is important for cellular function, however, tools enabling interrogation protein dynamics within native lipid environments are scarce often invasive. We show that styrene–maleic acid particle (SMALP) technology can be coupled with hydrogen–deuterium exchange mass spectrometry (HDX‐MS) to investigate conformational bilayers. demonstrate changes in accessibility rhomboid protease GlpG, captured three different compositions,...
Tripartite resistance nodulation and cell division multidrug efflux pumps span the periplasm are major drivers of among gram-negative bacteria. Cations, such as Mg2+, become concentrated within and, in contrast to cytoplasm, its pH is sensitive conditions outside cell. Here, we reveal an interplay between Mg2+ modulating structural dynamics periplasmic adapter protein, AcrA, function prototypical AcrAB-TolC pump from Escherichia coli. In absence AcrA becomes increasingly plastic acidic...
Photosystem 2 reaction centre complexes prepared either by solubilisation with Triton X-100 and subsequent exchange into dodecyl maltoside or a procedure involving combination of LiClO4, were characterised in terms chlorophyll a, pheophytin beta-carotene cytochrome b559 content. Time-resolved fluorescence decay kinetics measured using both types complexes. Our data show that the isolated photosystem two complex contain, for molecules, close to six one b559. No major differences observed...
The analytical toolkit developed for investigations into water-soluble protein folding has yet to be applied in earnest membrane proteins. A major problem is the difficulty collecting kinetic data, which are crucial understanding any reaction. Here, we combine and thermodynamic studies of reversible unfolding an alpha-helical provide a definitive value reaction free energy means probe transition state. Our analyses show that step SDS-induced denaturation bacteriorhodopsin involves reduction...
Photoinitiated polymerization-induced self-assembly (photo-PISA) is an efficient approach to predictably prepare polymeric nanostructures with a wide range of morphologies. Given that this process can be performed at high concentrations and under mild reaction conditions, it has the potential have significant industrial scope. However, given majority (and more specifically biotechnological) formulations contain mixtures polymers surfactants, effect such surfactants on PISA important...
The 19-mer synthetic peptide known as R5 has been used widely in studies of peptide-driven silica condensation. Despite this, the structure and function have not yet fully characterized. Here, we present a systematic study silicification focusing on three key variables: concentration peptide, precursor silicic acid, solution pH. Additionally, first secondary presence absence acid introduce one-dimensional two-dimensional NMR to probe both higher-order aggregation. We find that R5-directed is...
Proton-coupled transporters use transmembrane proton gradients to power active transport of nutrients inside the cell. High-resolution structures often fail capture coupling between and ligand binding, conformational changes associated with transport. We combine HDX-MS mutagenesis MD simulations dissect molecular mechanism prototypical transporter XylE. show that protonation a conserved aspartate triggers transition from outward-facing inward-facing state. This only occurs in presence...
The regeneration kinetics of the integral membrane protein bacteriorhodopsin have been investigated in a lipid-based refolding system. Previous studies on involved detergent-based systems, and particular mixed dimyristoylphosphatidylcholine (DMPC)/CHAPS micelles. Here, we show that short chain lipid dihexanoylphosphatidylcholine (DHPC) can be substituted for detergent CHAPS regenerated to high yield DMPC/DHPC Bacteriorhodopsin are measured Rapid, stopped flow mixing is employed initiate...
Three different lipid systems have been developed to investigate the effect of physicochemical forces within bilayer on folding integral membrane protein bacteriorhodopsin. Each system consists vesicles containing two species, one with phosphatidylcholine and other phosphatidylethanolamine headgroups, but same hydrocarbon chains: either L-alpha-1, 2-dioleoyl, L-alpha-1,2-dipalmitoleoyl, or L-alpha-1,2-dimyristoyl. Increasing mole fraction increases desire each monolayer leaflet in curve...
Very little is known about the folding of proteins within biological membranes. A "two-stage" model has been proposed on thermodynamic grounds for α helical, integral membrane proteins, first stage which involves formation transmembrane helices that are to behave as autonomous domains. Here, we investigate helix in bacteriorhodopsin and present a time-resolved circular dichroism study slow vitro this protein. We show that, although some protein's form early, significant part secondary...
Here we examined the gas-phase structures of two tetrameric membrane protein complexes by ion mobility mass spectrometry. The collision cross sections measured for channel are in accord with a compact configuration subunits, suggesting that native-like structure can be preserved under harsh activation conditions required to release it from detergent micelle into gas phase. We also found quaternary transporter, which has fewer transmembrane subunits than channel, is less stable once stripped...
Correctly folded membrane proteins underlie a plethora of cellular processes, but little is known about how they fold. Knowledge folding mechanisms centres on reversible chemically denatured proteins. However, this cannot replicate the unidirectional elongation protein chain during co-translational in cell, where insertion assisted by translocase apparatus. We show that lipid (devoid components) sufficient for successful two bacterial α-helical proteins, DsbB and GlpG. Folding spontaneous,...
Other than more widely used methods, the use of styrene maleic acid copolymers allows direct extraction membrane proteins from lipid bilayer into SMALPs keeping it in its native surrounding.