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Biology subjects

Ueda, G.

Publications and source records attributed to Ueda, G..

13 recordsLinked to original sources

De novo design of buttressed loops for sculpting protein functions

In natural proteins, structured loops play central roles in molecular recognition, signal transduction and enzyme catalysis. However, because of the intrinsic flexibility and irregularity of loop regions, organizing multiple structured loops at protein functional sites has been very difficult to achieve by de novo protein design. Here we describe a solution to this problem that generates structured loops buttressed by extensive hydrogen bonding interactions with two neighboring loops and with secondary structure elements. We use this approach to design tandem repeat proteins with buttressed loops ranging from 9 to 14 residues in length. Experimental characterization shows the designs are folded and monodisperse, highly soluble, and thermally stable. Crystal structures are in close agreement with the computational design models, with the loops structured and buttressed by their neighbors as designed. We demonstrate the functionality afforded by loop buttressing by designing and characterizing binders for extended peptides in which the loops form one side of an extended binding pocket. The ability to design multiple structured loops should contribute quite generally to efforts to design new protein functions.

biochemistry↗

De novo design of modular protein hydrogels with programmable intra- and extracellular viscoelasticity

Relating the macroscopic properties of protein-based materials to their underlying component microstructure is an outstanding challenge. Here, we exploit computational design to specify the size, flexibility, and valency of de novo protein building blocks, as well as the interaction dynamics between them, to investigate how molecular parameters govern the macroscopic viscoelasticity of the resultant protein hydrogels. We construct gel systems from pairs of symmetric protein homo-oligomers, each comprising 2, 5, 24, or 120 individual protein components, that are crosslinked either physically or covalently into idealized step-growth biopolymer networks. Through rheological assessment and molecular dynamics (MD) simulation, we find that the covalent linkage of multifunctional precursors yields hydrogels whose viscoelasticity depends on the crosslink length between the constituent building blocks. In contrast, reversibly crosslinking the homo-oligomeric components with a computationally designed heterodimer results in non-Newtonian biomaterials exhibiting fluid-like properties under rest and low shear, but shear-stiffening solid-like behavior at higher frequencies. Exploiting the unique genetic encodability of these materials, we demonstrate the assembly of protein networks within living mammalian cells and show via fluorescence recovery after photobleaching (FRAP) that mechanical properties can be tuned intracellularly, in correlation with matching formulations formed extracellularly. We anticipate that the ability to modularly construct and systematically program the viscoelastic properties of designer protein-based materials could have broad utility in biomedicine, with applications in tissue engineering, therapeutic delivery, and synthetic biology. SignificanceProtein-based hydrogels have many applications in cellular engineering and medicine. Most genetically encodable protein hydrogels are made from naturally harvested proteins or protein-polymer hybrid constructs. Here we describe de novo protein hydrogels and systematically investigate the impact of microscopic properties of the building blocks (e.g., supramolecular interaction, valencies, geometries, flexibility) on the resultant macroscopic gel mechanics, both intra-and extracellularly. These de novo supramolecular protein assemblies, whose properties can be tuned from solid gels to non-Newtonian fluids, provide expanded opportunities for applications in synthetic biology and medicine.

bioengineering↗

Antigen spacing on protein nanoparticles influences antibody responses to vaccination

Immunogen design approaches aim to control the specificity and quality of antibody responses to enable the creation of next-generation vaccines with improved potency and breadth. However, our understanding of the relationship between immunogen structure and immunogenicity is limited. Here we use computational protein design to generate a self-assembling nanoparticle vaccine platform based on the head domain of influenza hemagglutinin (HA) that enables precise control of antigen conformation, flexibility, and spacing on the nanoparticle exterior. Domain-based HA head antigens were presented either as monomers or in a native-like closed trimeric conformation that prevents exposure of trimer interface epitopes. These antigens were connected to the underlying nanoparticle by a rigid linker that was modularly extended to precisely control antigen spacing. We found that nanoparticle immunogens with decreased spacing between closed trimeric head antigens elicited antibodies with improved hemagglutination inhibition (HAI) and neutralization potency as well as binding breadth across diverse HAs within a subtype. Our "trihead" nanoparticle immunogen platform thus enables new insights into anti-HA immunity, establishes antigen spacing as an important parameter in structure-based vaccine design, and embodies several design features that could be used to generate next-generation vaccines against influenza and other viruses. HIGHLIGHTSO_LIComputational design of a closed trimeric HA head ("trihead") antigen platform. C_LIO_LIDesign of a rigid, extendable linker between displayed antigen and underlying protein nanoparticle enables precise variation of antigen spacing. C_LIO_LIDecreased antigen spacing of triheads elicits antibodies with the highest HAI, neutralizing activity, and cross-reactivity. C_LIO_LIChanges to antigen spacing alter epitope specificities of vaccine-elicited antibodies. C_LI

immunology↗

Computational design of non-porous, pH-responsive antibody nanoparticles

Programming protein nanomaterials to respond to changes in environmental conditions is a current challenge for protein design and important for targeted delivery of biologics. We describe the design of octahedral non-porous nanoparticles with the three symmetry axes (four-fold, three-fold, and two-fold) occupied by three distinct protein homooligomers: a de novo designed tetramer, an antibody of interest, and a designed trimer programmed to disassemble below a tunable pH transition point. The nanoparticles assemble cooperatively from independently purified components, and a cryo-EM density map reveals that the structure is very close to the computational design model. The designed nanoparticles can package a variety of molecular payloads, are endocytosed following antibody-mediated targeting of cell surface receptors, and undergo tunable pH-dependent disassembly at pH values ranging between to 5.9-6.7. To our knowledge, these are the first designed nanoparticles with more than two structural components and with finely tunable environmental sensitivity, and they provide new routes to antibody-directed targeted delivery.

bioengineering↗

Computational design of nanoscale rotational mechanics in de novo protein assemblies

Natural nanomachines like the F1/F0-ATPase contain protein components that undergo rotation relative to each other. Designing such mechanically constrained nanoscale protein architectures with internal degrees of freedom is an outstanding challenge for computational protein design. Here we explore the de novo construction of protein rotary machinery from designed axle and ring components. Using cryoelectron microscopy, we find that axle-ring systems assemble as designed and populate diverse rotational states depending on symmetry match or mismatch and the designed interface energy landscape. These mechanical systems with internal rotational degrees of freedom are a step towards the systematic design of genetically encodable nanomachines. One-Sentence SummaryComputationally designed self-assembling protein rotary machines sample internal degrees of freedom sculpted within the energy landscape.

synthetic biology↗

Multivalent designed proteins protect against SARS-CoV-2 variants of concern

Escape variants of SARS-CoV-2 are threatening to prolong the COVID-19 pandemic. To address this challenge, we developed multivalent protein-based minibinders as potential prophylactic and therapeutic agents. Homotrimers of single minibinders and fusions of three distinct minibinders were designed to geometrically match the SARS-CoV-2 spike (S) trimer architecture and were optimized by cell-free expression and found to exhibit virtually no measurable dissociation upon binding. Cryo-electron microscopy (cryoEM) showed that these trivalent minibinders engage all three receptor binding domains on a single S trimer. The top candidates neutralize SARS-CoV-2 variants of concern with IC50 values in the low pM range, resist viral escape, and provide protection in highly vulnerable human ACE2-expressing transgenic mice, both prophylactically and therapeutically. Our integrated workflow promises to accelerate the design of mutationally resilient therapeutics for pandemic preparedness. One-Sentence SummaryWe designed, developed, and characterized potent, trivalent miniprotein binders that provide prophylactic and therapeutic protection against emerging SARS-CoV-2 variants of concern.

synthetic biology↗

Designed proteins assemble antibodies into modular nanocages

Antibodies are widely used in biology and medicine, and there has been considerable interest in multivalent antibody formats to increase binding avidity and enhance signaling pathway agonism. However, there are currently no general approaches for forming precisely oriented antibody assemblies with controlled valency. We describe the computational design of two-component nanocages that overcome this limitation by uniting form and function. One structural component is any antibody or Fc fusion and the second is a designed Fc-binding homo-oligomer that drives nanocage assembly. Structures of 8 antibody nanocages determined by electron microscopy spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage match the corresponding computational models. Antibody nanocages targeting cell-surface receptors enhance signaling compared to free antibodies or Fc-fusions in DR5-mediated apoptosis, Tie2-mediated angiogenesis, CD40 activation, and T cell proliferation; nanocage assembly also increases SARS-CoV-2 pseudovirus neutralization by -SARS-CoV-2 monoclonal antibodies and Fc-ACE2 fusion proteins. We anticipate that the ability to assemble arbitrary antibodies without need for covalent modification into highly ordered assemblies with different geometries and valencies will have broad impact in biology and medicine.

biochemistry↗

F-domain valency determines outcome of signaling through the angiopoietin pathway

Angiopoietin 1 and 2 (Ang1 and Ang2) modulate angiogenesis and vascular homeostasis through engagement of their very similar F-domain modules with the Tie2 receptor tyrosine kinase on endothelial cells. Despite this similarity in the underlying receptor binding interaction, the two angiopoietins have opposite effects: Ang1 induces phosphorylation of protein kinase B (AKT), strengthens cell-cell junctions and enhances endothelial cell survival while Ang2 antagonizes these effects1-4. To investigate the molecular basis for the opposing effects, we examined the protein kinase activation and morphological phenotypes produced by a series of computationally designed protein scaffolds presenting the Ang1 F-domain in a wide range of valencies and geometries. We find two broad phenotypic classes distinguished by the number of presented F-domains: scaffolds presenting 4 F-domains have Ang2 like activity, upregulating pFAK and pERK but not pAKT, and failing to induce cell migration and tube formation, while scaffolds presenting 6 or more F-domains have Ang1 like activity, upregulating pAKT and inducing migration and tube formation. The scaffolds with 8 or more F-domains display superagonist activity, producing stronger phenotypes at lower concentrations than Ang1. When examined in vivo, superagonist icosahedral self-assembling nanoparticles caused significant revascularization in hemorrhagic brains after a controlled cortical impact injury.

biochemistry↗

Generation of ordered protein assemblies using rigid three-body fusion

Protein nanomaterial design is an emerging discipline with applications in medicine and beyond. A longstanding design approach uses genetic fusion to join protein homo-oligomer subunits via -helical linkers to form more complex symmetric assemblies, but this method is hampered by linker flexibility and a dearth of geometric solutions. Here, we describe a general computational method that performs rigid three-body fusion of homo-oligomer and spacer building blocks to generate user-defined architectures, while at the same time significantly increasing the number of geometric solutions over typical symmetric fusion. The fusion junctions are then optimized using Rosetta to minimize flexibility. We apply this method to design and test 92 dihedral symmetric protein assemblies from a set of designed homo-dimers and repeat protein building blocks. Experimental validation by native mass spectrometry, small angle X-ray scattering, and negative-stain single-particle electron microscopy confirms the assembly states for 11 designs. Most of these assemblies are constructed from DARPins (designed ankyrin repeat proteins), anchored on one end by -helical fusion and on the other by a designed homo-dimer interface, and we explored their use for cryo-EM structure determination by incorporating DARPin variants selected to bind targets of interest. Although the target resolution was limited by preferred orientation effects, small scaffold size, and the low-order symmetry of these dihedral scaffolds, we found that the dual anchoring strategy reduced the flexibility of the target-DARPIN complex with respect to the overall assembly, suggesting that multipoint anchoring of binding domains could contribute to cryo-EM structure determination of small proteins.

synthetic biology↗

Elicitation of broadly protective immunity to influenza by multivalent hemagglutinin nanoparticle vaccines

Influenza vaccines that confer broad and durable protection against diverse virus strains would have a major impact on global health. However, next-generation vaccine design efforts have been complicated by challenges including the genetic plasticity of the virus and the immunodominance of certain epitopes in its glycoprotein antigens. Here we show that computationally designed, two-component nanoparticle immunogens induce potently neutralizing and broadly protective antibody responses against a wide variety of influenza viruses. The nanoparticle immunogens display 20 hemagglutinin (HA) trimers in a highly immunogenic array, and their assembly in vitro enables precisely controlled co-display of multiple distinct HAs in defined ratios. Nanoparticle immunogens displaying the four HAs of licensed quadrivalent influenza vaccines (QIV) elicited hemagglutination inhibition and neutralizing antibody responses to vaccine-matched strains that were equivalent or superior to commercial QIV in mice, ferrets, and nonhuman primates. The nanoparticle immunogens--but not QIV--simultaneously induced broadly protective antibody responses to heterologous viruses, including H5N1 and H7N9, by targeting the subdominant yet conserved HA stem. Unlike previously reported influenza vaccine candidates, our nanoparticle immunogens can alter the intrinsic immunodominance hierarchy of HA to induce both potent receptor-blocking and broadly cross-reactive stem-directed antibody responses and are attractive candidates for a next-generation influenza vaccine that could replace current seasonal vaccines. One Sentence SummaryNanoparticle immunogens displaying four seasonal influenza hemagglutinins elicit neutralizing antibodies directed at both the immunodominant head and the conserved stem and confer broad protective immunity.

immunology↗

Targeting HIV Env immunogens to B cell follicles in non-human primates through immune complex or protein nanoparticle formulations

Following immunization, high affinity antibody responses develop within germinal centers (GCs), specialized sites within follicles of the lymph node (LN) where B cells proliferate and undergo somatic hypermutation. Antigen availability within GCs is important, as B cells must acquire and present antigen to follicular helper T cells to drive this process. However, recombinant protein immunogens such as soluble HIV envelope (Env) trimers do not efficiently accumulate in follicles following traditional immunization. Here we demonstrate two strategies to concentrate HIV Env immunogens in follicles, via the formation of immune complexes (ICs) or by employing self-assembling protein nanoparticles for multivalent display of Env antigens. Using rhesus macaques, we show that within a few days following immunization, free trimers were present in a diffuse pattern in draining LNs, while trimer ICs and Env nanoparticles accumulated in B cell follicles. Whole LN imaging strikingly revealed that ICs and trimer nanoparticles concentrated in as many as 500 follicles in a single lymph node within 2 days after immunization. Imaging of LNs collected 7 days post-immunization showed that Env nanoparticles persisted on follicular dendritic cells in the light zone of nascent germinal centers. These findings suggest that the form of antigen administered in vaccination can dramatically impact localization in lymphoid tissues and provides a new rationale for the enhanced immune responses observed following immunization with immune complexes or nanoparticles.

immunology↗

Structural and functional evaluation of de novo-designed, two-component nanoparticle carriers for HIV Env trimer immunogens

Two-component, self-assembling nanoparticles represent a versatile platform for multivalent presentation of viral antigens. Nanoparticles of different sizes and geometries can be designed and combined with appropriate antigens to fit the requirements of different immunization strategies. Here, we describe detailed antigenic, structural, and functional characterization of computationally designed tetrahedral, octahedral, and icosahedral nanoparticle immunogens displaying trimeric HIV envelope glycoprotein (Env) ectodomains. Env trimers, based on subtype A (BG505) or consensus group M (ConM) sequences and engineered with SOSIP stabilizing mutations, were fused to the underlying trimeric building block of each nanoparticle. Initial screening yielded one icosahedral and two tetrahedral nanoparticle candidates, capable of presenting twenty or four copies of the Env trimer. A number of analyses, including detailed structural characterization by cryo-EM, demonstrated that the nanoparticle immunogens possessed the intended structural and antigenic properties. Comparing the humoral responses elicited by ConM-SOSIP trimers presented on a two-component tetrahedral nanoparticle to the corresponding soluble protein revealed that multivalent presentation increased the proportion of the overall antibody response directed against autologous neutralizing Ab epitopes present on the ConM-SOSIP trimers. Author SummaryProtein constructs based on soluble ectodomains of HIV glycoprotein (Env) trimers are the basis of many current HIV vaccine platforms. Multivalent antigen display is one strategy applied to improve the immunogenicity of different subunit vaccine candidates. Here, we describe and comprehensively evaluate a library of de novo designed, protein nanoparticles of different geometries for their ability to present trimeric Env antigens. We found three nanoparticle candidates that can stably incorporate model Env trimer on their surface while maintaining its structure and antigenicity. Immunogenicity of the designed nanoparticles is assessed in vitro and in vivo. In addition to introducing a novel set of reagents for multivalent display of Env trimers, this work provides both guiding principles and a detailed experimental roadmap for the generation, characterization, and optimization of Env-presenting, self-assembling nanoparticle immunogens.

immunology↗

Tailored Design of Protein Nanoparticle Scaffolds for Multivalent Presentation of Viral Glycoprotein Antigens

The adaptive immune system is highly sensitive to arrayed antigens, and multivalent display of viral glycoproteins on symmetric scaffolds has been found to substantially increase the elicitation of antigen-specific antibodies. Motivated by the considerable promise of this strategy for next-generation anti-viral vaccines, we set out to design new self-assembling protein nanoparticles with geometries specifically tailored to scaffold ectodomains of different viral glycoproteins. We first designed and characterized homo-trimers from designed repeat proteins with N-terminal helices positioned to match the C termini of several viral glycoprotein trimers. Oligomers found to experimentally adopt the designed configuration were then used to generate nanoparticles with tetrahedral, octahedral, or icosahedral symmetry. Examples of all three target symmetries were experimentally validated by cryo-electron microscopy and several were assessed for their ability to display viral glycoproteins via genetic fusion. Electron microscopy and antibody binding experiments demonstrated that the designed nanoparticles display conformationally intact native-like HIV-1 Env, influenza hemagglutinin, and prefusion RSV F trimers in the predicted geometries. This work demonstrates that novel nanoparticle immunogens can be designed from the bottom up with atomic-level accuracy and provides a general strategy for precisely controlling epitope presentation and accessibility.

synthetic biology↗