Structure of orthoreovirus RNA chaperone σNS, a component of viral replication factories Zhao, Boyang In: 2024. @article{noKey,
title = {Structure of orthoreovirus RNA chaperone σNS, a component of viral replication factories},
author = {Zhao, Boyang},
url = {https://www.nature.com/articles/s41467-024-46627-8#Sec15},
doi = {https://doi.org/10.1038/s41467-024-46627-8},
year = {2024},
date = {2024-01-01},
abstract = {The mammalian orthoreovirus (reovirus) σNS protein is required for formation of replication compartments that support viral genome replication and capsid assembly. Despite its functional importance, a mechanistic understanding of σNS is lacking. We conducted structural and biochemical analyses of a σNS mutant that forms dimers instead of the higher-order oligomers formed by wildtype (WT) σNS. The crystal structure shows that dimers interact with each other using N-terminal arms to form a helical assembly resembling WT σNS filaments in complex with RNA observed using cryo-EM. The interior of the helical assembly is of appropriate diameter to bind RNA. The helical assembly is disrupted by bile acids, which bind to the same site as the N-terminal arm. This finding suggests that the N-terminal arm functions in conferring context-dependent oligomeric states of σNS, which is supported by the structure of σNS lacking an N-terminal arm. We further observed that σNS has RNA chaperone activity likely essential for presenting mRNA to the viral polymerase for genome replication. This activity is reduced by bile acids and abolished by N-terminal arm deletion, suggesting that the activity requires formation of σNS oligomers. Our studies provide structural and mechanistic insights into the function of σNS in reovirus replication.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
The mammalian orthoreovirus (reovirus) σNS protein is required for formation of replication compartments that support viral genome replication and capsid assembly. Despite its functional importance, a mechanistic understanding of σNS is lacking. We conducted structural and biochemical analyses of a σNS mutant that forms dimers instead of the higher-order oligomers formed by wildtype (WT) σNS. The crystal structure shows that dimers interact with each other using N-terminal arms to form a helical assembly resembling WT σNS filaments in complex with RNA observed using cryo-EM. The interior of the helical assembly is of appropriate diameter to bind RNA. The helical assembly is disrupted by bile acids, which bind to the same site as the N-terminal arm. This finding suggests that the N-terminal arm functions in conferring context-dependent oligomeric states of σNS, which is supported by the structure of σNS lacking an N-terminal arm. We further observed that σNS has RNA chaperone activity likely essential for presenting mRNA to the viral polymerase for genome replication. This activity is reduced by bile acids and abolished by N-terminal arm deletion, suggesting that the activity requires formation of σNS oligomers. Our studies provide structural and mechanistic insights into the function of σNS in reovirus replication. |
Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features Roger, Magali In: 2024. @article{noKey,
title = {Beyond the coupled distortion model: structural analysis of the single domain cupredoxin AcoP, a green mononuclear copper centre with original features},
author = {Roger, Magali},
url = {https://pubs.rsc.org/en/content/articlehtml/2024/dt/d3dt03372d},
doi = {10.1039/D3DT03372D},
year = {2024},
date = {2024-01-01},
abstract = {Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discovery of novel cupredoxins demonstrates the high diversity of this family, with variations in terms of copper-binding ligands, copper centre geometry, redox potential, as well as biological function. AcoP is a periplasmic cupredoxin belonging to the iron respiratory chain of the acidophilic bacterium Acidithiobacillus ferrooxidans. AcoP presents original features, including high resistance to acidic pH and a constrained green-type copper centre of high redox potential. To understand the unique properties of AcoP, we undertook structural and biophysical characterization of wild-type AcoP and of two Cu-ligand mutants (H166A and M171A). The crystallographic structures, including native reduced AcoP at 1.65 Å resolution, unveil a typical cupredoxin fold. The presence of extended loops, never observed in previously characterized cupredoxins, might account for the interaction of AcoP with physiological partners. The Cu-ligand distances, determined by both X-ray diffraction and EXAFS, show that the AcoP metal centre seems to present both T1 and T1.5 features, in turn suggesting that AcoP might not fit well to the coupled distortion model. The crystal structures of two AcoP mutants confirm that the active centre of AcoP is highly constrained. Comparative analysis with other cupredoxins of known structures, suggests that in AcoP the second coordination sphere might be an important determinant of active centre rigidity due to the presence of an extensive hydrogen bond network. Finally, we show that other cupredoxins do not perfectly follow the coupled distortion model as well, raising the suspicion that further alternative models to describe copper centre geometries need to be developed, while the importance of rack-induced contributions should not be underestimated.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
Cupredoxins are widely occurring copper-binding proteins with a typical Greek-key beta barrel fold. They are generally described as electron carriers that rely on a T1 copper centre coordinated by four ligands provided by the folded polypeptide. The discovery of novel cupredoxins demonstrates the high diversity of this family, with variations in terms of copper-binding ligands, copper centre geometry, redox potential, as well as biological function. AcoP is a periplasmic cupredoxin belonging to the iron respiratory chain of the acidophilic bacterium Acidithiobacillus ferrooxidans. AcoP presents original features, including high resistance to acidic pH and a constrained green-type copper centre of high redox potential. To understand the unique properties of AcoP, we undertook structural and biophysical characterization of wild-type AcoP and of two Cu-ligand mutants (H166A and M171A). The crystallographic structures, including native reduced AcoP at 1.65 Å resolution, unveil a typical cupredoxin fold. The presence of extended loops, never observed in previously characterized cupredoxins, might account for the interaction of AcoP with physiological partners. The Cu-ligand distances, determined by both X-ray diffraction and EXAFS, show that the AcoP metal centre seems to present both T1 and T1.5 features, in turn suggesting that AcoP might not fit well to the coupled distortion model. The crystal structures of two AcoP mutants confirm that the active centre of AcoP is highly constrained. Comparative analysis with other cupredoxins of known structures, suggests that in AcoP the second coordination sphere might be an important determinant of active centre rigidity due to the presence of an extensive hydrogen bond network. Finally, we show that other cupredoxins do not perfectly follow the coupled distortion model as well, raising the suspicion that further alternative models to describe copper centre geometries need to be developed, while the importance of rack-induced contributions should not be underestimated. |
Molecular Rules Underpinning Enhanced Affinity Binding of Human T Cell Receptors Engineered for Immunotherapy Crean, Rory M., MacLachlan, Bruce J. In: 2020. @article{noKey,
title = {Molecular Rules Underpinning Enhanced Affinity Binding of Human T Cell Receptors Engineered for Immunotherapy},
author = {Crean, Rory M., MacLachlan, Bruce J.},
url = {https://www.cell.com/molecular-therapy-family/oncolytics/fulltext/S2372-7705(20)30112-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2372770520301121%3Fshowall%3Dtrue},
doi = {https://doi.org/10.1016/j.omto.2020.07.008},
year = {2020},
date = {2020-01-01},
abstract = {Immuno-oncology approaches that utilize T cell receptors (TCRs) are becoming highly attractive because of their potential to target virtually all cellular proteins, including cancer-specific epitopes, via the recognition of peptide-human leukocyte antigen (pHLA) complexes presented at the cell surface. However, because natural TCRs generally recognize cancer-derived pHLAs with very weak affinities, efforts have been made to enhance their binding strength, in some cases by several million-fold. In this study, we investigated the mechanisms underpinning human TCR affinity enhancement by comparing the crystal structures of engineered enhanced affinity TCRs with those of their wild-type progenitors. Additionally, we performed molecular dynamics simulations to better understand the energetic mechanisms driving the affinity enhancements. These data demonstrate that supra-physiological binding affinities can be achieved without altering native TCR-pHLA binding modes via relatively subtle modifications to the interface contacts, often driven through the addition of buried hydrophobic residues. Individual energetic components of the TCR-pHLA interaction governing affinity enhancements were distinct and highly variable for each TCR, often resulting from additive, or knock-on, effects beyond the mutated residues. This comprehensive analysis of affinity-enhanced TCRs has important implications for the future rational design of engineered TCRs as efficacious and safe drugs for cancer treatment.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
Immuno-oncology approaches that utilize T cell receptors (TCRs) are becoming highly attractive because of their potential to target virtually all cellular proteins, including cancer-specific epitopes, via the recognition of peptide-human leukocyte antigen (pHLA) complexes presented at the cell surface. However, because natural TCRs generally recognize cancer-derived pHLAs with very weak affinities, efforts have been made to enhance their binding strength, in some cases by several million-fold. In this study, we investigated the mechanisms underpinning human TCR affinity enhancement by comparing the crystal structures of engineered enhanced affinity TCRs with those of their wild-type progenitors. Additionally, we performed molecular dynamics simulations to better understand the energetic mechanisms driving the affinity enhancements. These data demonstrate that supra-physiological binding affinities can be achieved without altering native TCR-pHLA binding modes via relatively subtle modifications to the interface contacts, often driven through the addition of buried hydrophobic residues. Individual energetic components of the TCR-pHLA interaction governing affinity enhancements were distinct and highly variable for each TCR, often resulting from additive, or knock-on, effects beyond the mutated residues. This comprehensive analysis of affinity-enhanced TCRs has important implications for the future rational design of engineered TCRs as efficacious and safe drugs for cancer treatment. |
CD4+ T Cells Recognize Conserved Influenza A Epitopes through Shared Patterns of V-Gene Usage and Complementary Biochemical Features Watson, Alexander Greenshields-, Attaf, Meriem In: 2020. @article{noKey,
title = {CD4+ T Cells Recognize Conserved Influenza A Epitopes through Shared Patterns of V-Gene Usage and Complementary Biochemical Features},
author = {Watson, Alexander Greenshields-, Attaf, Meriem},
url = {https://www.cell.com/cell-reports/fulltext/S2211-1247(20)30866-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2211124720308664%3Fshowall%3Dtrue},
doi = {https://doi.org/10.1016/j.celrep.2020.107885},
year = {2020},
date = {2020-01-01},
abstract = {T cell recognition of peptides presented by human leukocyte antigens (HLAs) is mediated by the highly variable T cell receptor (TCR). Despite this built-in TCR variability, individuals can mount immune responses against viral epitopes by using identical or highly related TCRs expressed on CD8+ T cells. Characterization of these TCRs has extended our understanding of the molecular mechanisms that govern the recognition of peptide-HLA. However, few examples exist for CD4+ T cells. Here, we investigate CD4+ T cell responses to the internal proteins of the influenza A virus that correlate with protective immunity. We identify five internal epitopes that are commonly recognized by CD4+ T cells in five HLA-DR1+ subjects and show conservation across viral strains and zoonotic reservoirs. TCR repertoire analysis demonstrates several shared gene usage biases underpinned by complementary biochemical features evident in a structural comparison. These epitopes are attractive targets for vaccination and other T cell therapies.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
T cell recognition of peptides presented by human leukocyte antigens (HLAs) is mediated by the highly variable T cell receptor (TCR). Despite this built-in TCR variability, individuals can mount immune responses against viral epitopes by using identical or highly related TCRs expressed on CD8+ T cells. Characterization of these TCRs has extended our understanding of the molecular mechanisms that govern the recognition of peptide-HLA. However, few examples exist for CD4+ T cells. Here, we investigate CD4+ T cell responses to the internal proteins of the influenza A virus that correlate with protective immunity. We identify five internal epitopes that are commonly recognized by CD4+ T cells in five HLA-DR1+ subjects and show conservation across viral strains and zoonotic reservoirs. TCR repertoire analysis demonstrates several shared gene usage biases underpinned by complementary biochemical features evident in a structural comparison. These epitopes are attractive targets for vaccination and other T cell therapies. |
Specificity of bispecific T cell receptors and antibodies targeting peptide-HLA Holland, Christopher J., Crean, Rory M. In: 2020. @article{noKey,
title = {Specificity of bispecific T cell receptors and antibodies targeting peptide-HLA},
author = {Holland, Christopher J., Crean, Rory M.},
url = {https://www.jci.org/articles/view/130562},
doi = {https://doi.org/10.1172/JCI130562.},
year = {2020},
date = {2020-01-01},
abstract = {Tumor-associated peptide–human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface–expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
Tumor-associated peptide–human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface–expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents. |
Structure of CC Chemokine Receptor 5 with a Potent Chemokine Antagonist Reveals Mechanisms of Chemokine Recognition and Molecular Mimicry by HIV Zheng, Yi, Han, Gye Won In: 2018. @article{noKey,
title = {Structure of CC Chemokine Receptor 5 with a Potent Chemokine Antagonist Reveals Mechanisms of Chemokine Recognition and Molecular Mimicry by HIV},
author = {Zheng, Yi, Han, Gye Won},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5572563/},
doi = {https://doi.org/10.1016/j.immuni.2017.05.002},
year = {2018},
date = {2018-01-01},
abstract = {CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
CCR5 is the primary chemokine receptor utilized by HIV to infect leukocytes, whereas CCR5 ligands inhibit infection by blocking CCR5 engagement with HIV gp120. To guide the design of improved therapeutics, we solved the structure of CCR5 in complex with chemokine antagonist [5P7]CCL5. Several structural features appeared to contribute to the anti-HIV potency of [5P7]CCL5, including the distinct chemokine orientation relative to the receptor, the near-complete occupancy of the receptor binding pocket, the dense network of intermolecular hydrogen bonds, and the similarity of binding determinants with the FDA-approved HIV inhibitor Maraviroc. Molecular modeling indicated that HIV gp120 mimicked the chemokine interaction with CCR5, providing an explanation for the ability of CCR5 to recognize diverse ligands and gp120 variants. Our findings reveal that structural plasticity facilitates receptor-chemokine specificity and enables exploitation by HIV, and provide insight into the design of small molecule and protein inhibitors for HIV and other CCR5-mediated diseases. |
In meso Structure of the Cobalamin Transporter, BtuB, at 1.95 Å Resolution Cherezov, V., Yamashita, E. In: 2006. @article{noKey,
title = {In meso Structure of the Cobalamin Transporter, BtuB, at 1.95 Å Resolution},
author = {Cherezov, V., Yamashita, E.},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1808586/},
doi = {https://doi.org/10.1016/j.jmb.2006.09.022},
year = {2006},
date = {2006-01-01},
abstract = {Crystals of the apo-form of the vitamin B12 and colicin transporter, BtuB, that diffract to 1.95 Å have been grown by the membrane-based in meso technique. The structure of the protein differs in several details from that of its counterpart grown by the more traditional, detergent-based (in surfo) method. Some of these differences include i) the five N-terminal residues are resolved in meso, ii) residues 57–62 in the hatch domain and residues 574–581 in loop 21–22 are disordered in meso and are ordered in surfo, iii) residues 278–287 in loop 7–8 are resolved in meso, iv) residues 324–331 in loop 9–10, 396–411 in loop 13–14, 442–458 in loop 15–16 and 526–541 in loop 19–20 have large differences in position between the two crystal forms, as have residues 86–96 in the hatch domain, and v) the conformation of residues 6 and 7 in the Ton box (considered critical to signal transduction and substrate transport) are entirely different in the two structures. Importantly, the in meso orientation of residues 6 and 7 is similar to that of the vitamin B12-charged state. These data suggest that the 'substrate-induced' 180-degree rotation of residues 6 and 7 reported in the literature may not be a unique signaling event. The extent to which these findings agree with structural, dynamic and functional insights gleaned from site-directed spin labeling and electron paramagnetic resonance measurements is evaluated. Packing in in meso-grown crystals is dense and layered, consistent with the current model for crystallogenesis of membrane proteins in lipidic mesophases. Layered packing has been used to locate the transmembrane hydrophobic surface of the protein. Generally, this is consistent with tryptophan, tyrosine, lipid and Cα-B-factor distributions in the protein, and with predictions based on transfer free energy calculations.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
Crystals of the apo-form of the vitamin B12 and colicin transporter, BtuB, that diffract to 1.95 Å have been grown by the membrane-based in meso technique. The structure of the protein differs in several details from that of its counterpart grown by the more traditional, detergent-based (in surfo) method. Some of these differences include i) the five N-terminal residues are resolved in meso, ii) residues 57–62 in the hatch domain and residues 574–581 in loop 21–22 are disordered in meso and are ordered in surfo, iii) residues 278–287 in loop 7–8 are resolved in meso, iv) residues 324–331 in loop 9–10, 396–411 in loop 13–14, 442–458 in loop 15–16 and 526–541 in loop 19–20 have large differences in position between the two crystal forms, as have residues 86–96 in the hatch domain, and v) the conformation of residues 6 and 7 in the Ton box (considered critical to signal transduction and substrate transport) are entirely different in the two structures. Importantly, the in meso orientation of residues 6 and 7 is similar to that of the vitamin B12-charged state. These data suggest that the 'substrate-induced' 180-degree rotation of residues 6 and 7 reported in the literature may not be a unique signaling event. The extent to which these findings agree with structural, dynamic and functional insights gleaned from site-directed spin labeling and electron paramagnetic resonance measurements is evaluated. Packing in in meso-grown crystals is dense and layered, consistent with the current model for crystallogenesis of membrane proteins in lipidic mesophases. Layered packing has been used to locate the transmembrane hydrophobic surface of the protein. Generally, this is consistent with tryptophan, tyrosine, lipid and Cα-B-factor distributions in the protein, and with predictions based on transfer free energy calculations. |
Room to move: crystallizing membrane proteins in swollen lipidic mesophases Cherezov, Vadim, Clogston, Jeffrey In: 2006. @article{noKey,
title = {Room to move: crystallizing membrane proteins in swollen lipidic mesophases},
author = {Cherezov, Vadim, Clogston, Jeffrey},
url = {https://pubmed.ncbi.nlm.nih.gov/16490208/},
doi = {https://doi.org/10.1016/j.jmb.2006.01.049},
year = {2006},
date = {2006-01-01},
abstract = {The cubic phase or in meso crystallization method is responsible for almost 40 solved integral membrane protein structures. Most of these are small and compact proteins. A model for how crystals form by the in meso method has been proposed that invokes a transition between mesophases. In light of this model, we speculated that a more hydrated and open mesophase, of reduced interfacial curvature, would support facile crystallization of bigger and bulkier proteins. The proposal was explored here by performing crystallization in the presence of additives that swell the cubic phase. The additive concentration inducing swelling, as quantified by small-angle X-ray diffraction, coincided with a "crystallization window" in which two, very different transmembranal proteins produced crystals. That the swollen mesophase can grow structure-grade crystals was proven with one of these, the light-harvesting II complex. In most regards, the structural details of the corresponding complex resembled those of crystals grown by the conventional vapour diffusion method, with some important differences. In particular, packing density in the in meso-grown crystals was dramatically higher, more akin to that seen with water-soluble proteins, which accounts for their enhanced diffracting power. The layered and close in-plane packing observed has been rationalized in a model for nucleation and crystal growth by the in meso method that involves swollen mesophases. These results present a rational case for including mesophase-swelling additives in screens for in meso crystallogenesis. Their use will contribute to broadening the range of membrane proteins that yield to structure determination.},
keywords = {ROCKIMAGER},
pubstate = {published},
tppubtype = {article}
}
The cubic phase or in meso crystallization method is responsible for almost 40 solved integral membrane protein structures. Most of these are small and compact proteins. A model for how crystals form by the in meso method has been proposed that invokes a transition between mesophases. In light of this model, we speculated that a more hydrated and open mesophase, of reduced interfacial curvature, would support facile crystallization of bigger and bulkier proteins. The proposal was explored here by performing crystallization in the presence of additives that swell the cubic phase. The additive concentration inducing swelling, as quantified by small-angle X-ray diffraction, coincided with a "crystallization window" in which two, very different transmembranal proteins produced crystals. That the swollen mesophase can grow structure-grade crystals was proven with one of these, the light-harvesting II complex. In most regards, the structural details of the corresponding complex resembled those of crystals grown by the conventional vapour diffusion method, with some important differences. In particular, packing density in the in meso-grown crystals was dramatically higher, more akin to that seen with water-soluble proteins, which accounts for their enhanced diffracting power. The layered and close in-plane packing observed has been rationalized in a model for nucleation and crystal growth by the in meso method that involves swollen mesophases. These results present a rational case for including mesophase-swelling additives in screens for in meso crystallogenesis. Their use will contribute to broadening the range of membrane proteins that yield to structure determination. |
