The Experts below are selected from a list of 21660 Experts worldwide ranked by ideXlab platform
Christina I. Schroeder - One of the best experts on this subject based on the ideXlab platform.
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Efficient enzymatic ligation of inhibitor cystine knot spider venom peptides: using sortase a to form double-knottins that probe voltage-gated sodium channel NaV1.7
Bioconjugate chemistry, 2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provid...
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Efficient Enzymatic Ligation of Inhibitor Cystine Knot Spider Venom Peptides: Using Sortase A To Form Double-Knottins That Probe Voltage-Gated Sodium Channel NaV1.7
2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provide novel tools for enhancing our understanding of, and design strategies for, therapeutically relevant voltage-gated ion Channels
Akello J. Agwa - One of the best experts on this subject based on the ideXlab platform.
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Efficient enzymatic ligation of inhibitor cystine knot spider venom peptides: using sortase a to form double-knottins that probe voltage-gated sodium channel NaV1.7
Bioconjugate chemistry, 2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provid...
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Efficient Enzymatic Ligation of Inhibitor Cystine Knot Spider Venom Peptides: Using Sortase A To Form Double-Knottins That Probe Voltage-Gated Sodium Channel NaV1.7
2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provide novel tools for enhancing our understanding of, and design strategies for, therapeutically relevant voltage-gated ion Channels
Bernardo Celda - One of the best experts on this subject based on the ideXlab platform.
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solution structure of a d l alternating oligonorleucine as a model of double stranded antiparallel beta helix
Biopolymers, 2002Co-Authors: E Navarro, E Fenude, Bernardo CeldaAbstract:Conformational characteristics of alternating D,L linear peptides are of particular interest because of their capacity to form Transmembrane Channels with different transport properties, as some natural antibiotics do. Single- and double-stranded beta-helical structures are common for alternating D,L peptides. The stability of the beta-helix depends on several structural factors, such as the backbone peptide length, type and position of side chains, and nature of terminal groups. The NMR and molecular dynamics solution conformation of a synthetic alternating D,L-oligopeptide with 15 norleucines (XVMe) has been used as a model to get insight in to the conformational features of double-stranded beta-helix structures. The NH chemical shift values (delta(NH)) and long-range nuclear Overhauser effects (NOE) cross peaks, in particular interstrand connectivities, clearly point to an antiparallel double-stranded beta-helix for the XVMe major conformation in solution. An extensive set of distances (from NOE cross peaks) and H-bonds (from delta(NH)) has been included in the molecular dynamics calculations. The experimental NMR data and theoretical calculations clearly indicate that the most probable conformation of XVMe in solution is a double-strand antiparallel beta(5.6) increasing decreasing-helix structure.
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solution nmr structure of a d l alternating oligonorleucine as a model of beta helix
Biopolymers, 2001Co-Authors: E Navarro, R Tejero, E Fenude, Bernardo CeldaAbstract:beta-Helix structures are of particular interest due to their capacity to form Transmembrane Channels with different transport properties. However, the relatively large number of beta-helices configurations does not allow a direct conformational analysis of beta-helical oligopeptides. A synthetic alternating D,L-oligopeptide with twelve norleucines (XIIMe) has been used as a model to get insight in the conformational features of beta-helix structures. The spatial configuration of XIIMe in solution has been determined by NMR. An extensive set of distances (nuclear Overhauser effect) and dihedral (J coupling constants) constraints have been included in molecular dynamics calculations. The NMR experimental data and theoretical calculations clearly indicate that the XIIMe adopts a single beta(4.4)-helix-type conformation in nonpolar solvents.
Linda V. Blomster - One of the best experts on this subject based on the ideXlab platform.
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Efficient enzymatic ligation of inhibitor cystine knot spider venom peptides: using sortase a to form double-knottins that probe voltage-gated sodium channel NaV1.7
Bioconjugate chemistry, 2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provid...
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Efficient Enzymatic Ligation of Inhibitor Cystine Knot Spider Venom Peptides: Using Sortase A To Form Double-Knottins That Probe Voltage-Gated Sodium Channel NaV1.7
2018Co-Authors: Akello J. Agwa, Linda V. Blomster, Christina I. SchroederAbstract:Gating modifier toxins from spider venom are disulfide-rich peptides that typically comprise a stabilizing inhibitor cystine knot (ICK). These knottin peptides are being pursued as therapeutic leads for a range of conditions linked to Transmembrane proteins. Recently, double-knottin peptides discovered in spider venom and produced by recombinant expression have provided insights into the pharmacology of Transmembrane Channels. Here, we use chemoenzymatic ligation to produce double-knottins to probe the effect of bivalent modulation on the voltage-gated sodium channel subtype 1.7 (NaV1.7), which is implicated in pain signaling. Monovalent knottins were oxidatively folded and then biochemically conjugated using sortase A, to form double-knottins. The structural integrity of the peptides was confirmed using NMR, and fluorescence-based activity assays provided evidence suggesting that coincubated monovalent and bivalent knottins can cooperatively modulate NaV1.7. We anticipate that double-knottins will provide novel tools for enhancing our understanding of, and design strategies for, therapeutically relevant voltage-gated ion Channels
Mark C Leake - One of the best experts on this subject based on the ideXlab platform.
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correlating single molecule characteristics of the yeast aquaglyceroporin fps1 with environmental perturbations directly in living cells
Methods, 2021Co-Authors: Sviatlana Shashkova, Mikael Andersson, Stefan Hohmann, Mark C LeakeAbstract:Membrane proteins play key roles at the interface between the cell and its environment by mediating selective import and export of molecules via plasma membrane Channels. Despite a multitude of studies on Transmembrane Channels, understanding of their dynamics directly within living systems is limited. To address this, we correlated molecular scale information from living cells with real time changes to their microenvironment. We employed super-resolved millisecond fluorescence microscopy with a single-molecule sensitivity, to track labelled molecules of interest in real time. We use as example the aquaglyceroporin Fps1 in the yeast Saccharomyces cerevisiae to dissect and correlate its stoichiometry and molecular turnover kinetics with various extracellular conditions. We show that Fps1 resides in multi tetrameric clusters while hyperosmotic and oxidative stress conditions cause Fps1 reorganization. Moreover, we demonstrate that rapid exposure to hydrogen peroxide causes Fps1 degradation. In this way we shed new light on aspects of architecture and dynamics of glycerol-permeable plasma membrane Channels.
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correlating single molecule characteristics of the yeast aquaglyceroporin fps1 with environmental perturbations directly in living cells
bioRxiv, 2020Co-Authors: Sviatlana Shashkova, Mikael Andersson, Stefan Hohmann, Mark C LeakeAbstract:Abstract Membrane proteins play key roles at the interface between the cell and its environment by mediating selective import and export of molecules via plasma membrane Channels. Despite a multitude of studies on Transmembrane Channels, understanding of their dynamics directly within living systems is limited. To address this, we correlated molecular scale information from living cells with real time changes to their microenvironment. We employed super-resolved millisecond fluorescence microscopy with a single-molecule sensitivity, to track labelled molecules of interest in real time. We use as example the aquaglyceroporin Fps1 in the yeast Saccharomyces cerevisiae to dissect and correlate its stoichiometry and molecular turnover kinetics with various extracellular conditions. In this way we shed new light on aspects of architecture and dynamics of glycerol-permeable plasma membrane Channels.
