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Proceedings of the National Academy of... May 2023Integral membrane protein structure determination traditionally requires extraction from cell membranes using detergents or polymers. Here, we describe the isolation and...
Integral membrane protein structure determination traditionally requires extraction from cell membranes using detergents or polymers. Here, we describe the isolation and structure determination of proteins in membrane vesicles derived directly from cells. Structures of the ion channel Slo1 from total cell membranes and from cell plasma membranes were determined at 3.8 Å and 2.7 Å resolution, respectively. The plasma membrane environment stabilizes Slo1, revealing an alteration of global helical packing, polar lipid, and cholesterol interactions that stabilize previously unresolved regions of the channel and an additional ion binding site in the Ca regulatory domain. The two methods presented enable structural analysis of both internal and plasma membrane proteins without disrupting weakly interacting proteins, lipids, and cofactors that are essential to biological function.
Topics: Membrane Proteins; Cell Membrane; Ion Channels; Binding Sites
PubMed: 37098056
DOI: 10.1073/pnas.2302325120 -
Journal of the Royal Society, Interface Apr 2018This review highlights recent development of biosensors that use the functions of membrane proteins. Membrane proteins are essential components of biological membranes... (Review)
Review
This review highlights recent development of biosensors that use the functions of membrane proteins. Membrane proteins are essential components of biological membranes and have a central role in detection of various environmental stimuli such as olfaction and gustation. A number of studies have attempted for development of biosensors using the sensing property of these membrane proteins. Their specificity to target molecules is particularly attractive as it is significantly superior to that of traditional human-made sensors. In this review, we classified the membrane protein-based biosensors into two platforms: the lipid bilayer-based platform and the cell-based platform. On lipid bilayer platforms, the membrane proteins are embedded in a lipid bilayer that bridges between the protein and a sensor device. On cell-based platforms, the membrane proteins are expressed in a cultured cell, which is then integrated in a sensor device. For both platforms we introduce the fundamental information and the recent progress in the development of the biosensors, and remark on the outlook for practical biosensing applications.
Topics: Animals; Biosensing Techniques; Cell Membrane; HEK293 Cells; Humans; Lipid Bilayers; Membrane Proteins; MicroRNAs; Models, Molecular; Protein Engineering; Saccharomyces cerevisiae; Signal Transduction; Smell; Spodoptera; Xenopus laevis
PubMed: 29669891
DOI: 10.1098/rsif.2017.0952 -
Biochimica Et Biophysica Acta Jan 2014
Topics: Biophysics; Ligands; Membrane Proteins; Protein Binding; Protein Conformation
PubMed: 24206896
DOI: 10.1016/j.bbamem.2013.09.013 -
The Journal of Biological Chemistry Mar 2018My scientific career has taken me from chemistry, via theoretical physics and bioinformatics, to molecular biology and even structural biology. Along the way,...
My scientific career has taken me from chemistry, via theoretical physics and bioinformatics, to molecular biology and even structural biology. Along the way, serendipity led me to work on problems such as the identification of signal peptides that direct protein trafficking, membrane protein biogenesis, and cotranslational protein folding. I've had some great collaborations that came about because of a stray conversation or from following up on an interesting paper. And I've had the good fortune to be asked to sit on the Nobel Committee for Chemistry, where I am constantly reminded of the amazing pace and often intricate history of scientific discovery. Could I have planned this? No way! I just went with the flow ….
Topics: Animals; Chemical Engineering; Computational Biology; History, 20th Century; History, 21st Century; Humans; Lipid Bilayers; Membrane Proteins; Models, Molecular; Molecular Biology; New York City; Physics; Protein Folding; Protein Sorting Signals; Signal Transduction; Sweden
PubMed: 29523692
DOI: 10.1074/jbc.X118.001958 -
Annual Review of Cell and Developmental... Oct 2017Proper localization of membrane proteins is essential for the function of biological membranes and for the establishment of organelle identity within a cell. Molecular... (Review)
Review
Proper localization of membrane proteins is essential for the function of biological membranes and for the establishment of organelle identity within a cell. Molecular machineries that mediate membrane protein biogenesis need to not only achieve a high degree of efficiency and accuracy, but also prevent off-pathway aggregation events that can be detrimental to cells. The posttranslational targeting of tail-anchored proteins (TAs) provides tractable model systems to probe these fundamental issues. Recent advances in understanding TA-targeting pathways reveal sophisticated molecular machineries that drive and regulate these processes. These findings also suggest how an interconnected network of targeting factors, cochaperones, and quality control machineries together ensures robust membrane protein biogenesis.
Topics: Animals; Humans; Membrane Proteins; Models, Biological; Protein Sorting Signals; Protein Transport
PubMed: 28992441
DOI: 10.1146/annurev-cellbio-100616-060839 -
FEBS Letters Jul 2015Cell-free protein production has become a core technology in the rapidly spreading field of synthetic biology. In particular the synthesis of membrane proteins, highly... (Review)
Review
Cell-free protein production has become a core technology in the rapidly spreading field of synthetic biology. In particular the synthesis of membrane proteins, highly problematic proteins in conventional cellular production systems, is an ideal application for cell-free expression. A large variety of artificial as well as natural environments for the optimal co-translational folding and stabilization of membrane proteins can rationally be designed. The high success rate of cell-free membrane protein production allows to focus on individually selected targets and to modulate their functional and structural properties with appropriate supplements. The efficiency and robustness of lysates from Escherichia coli strains allow a wide diversity of applications and we summarize current strategies for the successful production of high quality membrane protein samples.
Topics: Cell-Free System; Escherichia coli; Membrane Proteins; Protein Biosynthesis; Protein Folding; Recombinant Proteins
PubMed: 25937121
DOI: 10.1016/j.febslet.2015.04.045 -
Science China. Life Sciences Jan 2015Membrane proteins are involved in various critical biological processes, and studying membrane proteins represents a major challenge in protein biochemistry. As shown by... (Review)
Review
Membrane proteins are involved in various critical biological processes, and studying membrane proteins represents a major challenge in protein biochemistry. As shown by both structural and functional studies, the membrane environment plays an essential role for membrane proteins. In vitro studies are reliant on the successful reconstitution of membrane proteins. This review describes the interaction between detergents and lipids that aids the understanding of the reconstitution processes. Then the techniques of detergent removal and a few useful techniques to refine the formed proteoliposomes are reviewed. Finally the applications of reconstitution techniques to study membrane proteins involved in Ca(2+) signaling are summarized.
Topics: Detergents; In Vitro Techniques; Membrane Proteins; Microscopy, Electron; Structure-Activity Relationship
PubMed: 25576454
DOI: 10.1007/s11427-014-4769-0 -
Biochemical Society Transactions Oct 2019The construction of artificial membrane proteins from first principles is of fundamental interest and holds considerable promise for new biotechnologies. This review... (Review)
Review
The construction of artificial membrane proteins from first principles is of fundamental interest and holds considerable promise for new biotechnologies. This review considers the potential advantages of adopting a strictly minimalist approach to the process of membrane protein design. As well as the practical benefits of miniaturisation and simplicity for understanding sequence-structure-function relationships, minimalism should also support the abstract conceptualisation of membrane proteins as modular components for synthetic biology. These ideas are illustrated with selected examples that focus upon α-helical membrane proteins, and which demonstrate how such minimalist membrane proteins might be integrated into living biosystems.
Topics: Biotechnology; Membrane Proteins; Structure-Activity Relationship; Synthetic Biology
PubMed: 31671181
DOI: 10.1042/BST20190170 -
FEBS Letters Aug 2014When taking up the gauntlet of studying membrane protein functionality, scientists are provided with a plethora of advantages, which can be exploited for the synthesis... (Review)
Review
When taking up the gauntlet of studying membrane protein functionality, scientists are provided with a plethora of advantages, which can be exploited for the synthesis of these difficult-to-express proteins by utilizing cell-free protein synthesis systems. Due to their hydrophobicity, membrane proteins have exceptional demands regarding their environment to ensure correct functionality. Thus, the challenge is to find the appropriate hydrophobic support that facilitates proper membrane protein folding. So far, various modes of membrane protein synthesis have been presented. Here, we summarize current state-of-the-art methodologies of membrane protein synthesis in biomimetic-supported systems. The correct folding and functionality of membrane proteins depend in many cases on their integration into a lipid bilayer and subsequent posttranslational modification. We highlight cell-free systems utilizing the advantages of biological membranes.
Topics: Animals; Biomimetic Materials; Cell Membrane; Cell-Free System; Humans; Membrane Proteins; Membranes, Artificial
PubMed: 24931371
DOI: 10.1016/j.febslet.2014.06.007 -
Biomolecules Mar 2014Understanding protein folding has been one of the great challenges in biochemistry and molecular biophysics. Over the past 50 years, many thermodynamic and kinetic... (Review)
Review
Understanding protein folding has been one of the great challenges in biochemistry and molecular biophysics. Over the past 50 years, many thermodynamic and kinetic studies have been performed addressing the stability of globular proteins. In comparison, advances in the membrane protein folding field lag far behind. Although membrane proteins constitute about a third of the proteins encoded in known genomes, stability studies on membrane proteins have been impaired due to experimental limitations. Furthermore, no systematic experimental strategies are available for folding these biomolecules in vitro. Common denaturing agents such as chaotropes usually do not work on helical membrane proteins, and ionic detergents have been successful denaturants only in few cases. Refolding a membrane protein seems to be a craftsman work, which is relatively straightforward for transmembrane β-barrel proteins but challenging for α-helical membrane proteins. Additional complexities emerge in multidomain membrane proteins, data interpretation being one of the most critical. In this review, we will describe some recent efforts in understanding the folding mechanism of membrane proteins that have been reversibly refolded allowing both thermodynamic and kinetic analysis. This information will be discussed in the context of current paradigms in the protein folding field.
Topics: Animals; Humans; Kinetics; Membrane Proteins; Protein Conformation; Protein Folding; Thermodynamics
PubMed: 24970219
DOI: 10.3390/biom4010354