Search

Selective detection of disease-associated changes in the glycocalyx is an emerging field in modern targeted therapies. Detecting minor glycan changes on the cell surface is a challenge exacerbated by the lack of correspondence between cellular DNA/RNA and glycan structures. We demonstrate that multivalent displays of lectins on DNA-barcoded phages—liquid lectin array (LiLA)—detect subtle differences in density of glycans on cells. LiLA constructs displaying 73 copies of diCBM40 (CBM) lectin per virion (φ-CBM 73) exhibit non-linear ON/OFF-like recognition of sialoglycans on the surface of normal and cancer cells. A high-valency φ-CBM 290 display, or soluble CBM protein, cannot amplify the subtle differences detected by φ-CBM 73. Similarly, multivalent displays of CBM and Siglec-7 detect differences in the glycocalyx between stem-like and non-stem populations in cancer. Multivalent display of lectins offer in situ detection of minor differences in glycocalyx in cells both in vitro and in vivo not feasible to currently available technologies. [Display omitted] • Liquid lectin array (LiLA) is a collection of DNA-barcoded lectin-phage conjugates • LiLA detects subtle changes in the glycocalyx of mammalian cells • DNA-barcoded lectin-phages are decodable by NGS and are in vivo compatible • Multivalent lectin presentation shows a steep ON/OFF response to sialic acid changes Glycans are ubiquitous, but they cannot be quantified directly using DNA-sequencing methods. Lima et al. demonstrate that DNA-barcoded multivalent lectin-phage conjugates enable multiplex profiling of the mammalian glycocalyx in vitro and in vivo. Next-generation sequencing of lectin-phage constructs detects subtle glycocalyx changes that are challenging to detect using traditional lectin reagents. [ABSTRACT FROM AUTHOR]

Taspase 1 is a unique protease not only pivotal for embryonic development but also implicated in leukemias and solid tumors. As such, this enzyme is a promising while still challenging therapeutic target, and with its protein structure featuring a flexible loop preceding the active site a versatile model system for drug development. Supramolecular ligands provide a promising complementary approach to traditional small‐molecule inhibitors. Recently, the multivalent arrangement of molecular tweezers allowed the successful targeting of Taspase 1's surface loop. With this study we now want to take the next logic step und utilize functional linker systems that not only allow the implementation of novel properties but also engage in protein surface binding. Consequently, we chose two different linker types differing from the original divalent assembly: a backbone with aggregation‐induced emission (AIE) properties to enable monitoring of binding and a calix[4]arene scaffold initially pre‐positioning the supramolecular binding units. With a series of four AIE‐equipped ligands with stepwise increased valency we demonstrated that the functionalized AIE linkers approach ligand binding affinities in the nanomolar range and allow efficient proteolytic inhibition of Taspase 1. Moreover, implementation of the calix[4]arene backbone further enhanced the ligands' inhibitory potential, pointing to a specific linker contribution. [ABSTRACT FROM AUTHOR]

Abstract Amyloid‐β (Aβ) is a pivotal biomarker in Alzheimer's disease (AD), attracting considerable attention from numerous researchers. There is uncertainty regarding whether clearing Aβ is beneficial or harmful to cognitive function. This question has been a central topic of research, especially given the lack of success in developing Aβ‐targeted drugs for AD. However, with the Food and Drug Administration's approval of Lecanemab as the first anti‐Aβ medication in July 2023, there is a significant shift in perspective on the potential of Aβ as a therapeutic target for AD. In light of this advancement, this review aims to illustrate and consolidate the molecular structural attributes and pathological ramifications of Aβ. Furthermore, it elucidates the determinants influencing its expression levels while delineating the gamut of extant Aβ‐targeted pharmacotherapies that have been subjected to clinical or preclinical evaluation. Subsequently, a comprehensive analysis is presented, dissecting the research landscape of Aβ across the domains above, culminating in the presentation of informed perspectives. Concluding reflections contemplate the supplementary advantages conferred by nanoparticle constructs, conceptualized within the framework of multivalent theory, within the milieu of AD diagnosis and therapeutic intervention, supplementing conventional modalities.

The stimulator of interferon genes (STING) pathway is a potent therapeutic target for innate immunity. Despite the efforts to develop pocket‐dependent small‐molecule STING agonists that mimic the endogenous STING ligand, cyclic guanosine monophosphate–adenosine monophosphate (cGAMP), most of these agonists showed disappointing results in clinical trials owing to the limitations of the STING pocket. In this study, we developed novel pocket‐independent STING‐activating agonists (piSTINGs), which act through multivalency‐driven oligomerization to activate STING. Additionally, a piSTING‐adjuvanted vaccine elicited a significant antibody response and inhibited tumour growth in therapeutic models. Moreover, a piSTING‐based vaccine combination with aPD‐1 showed remarkable potential to enhance the effectiveness of immune checkpoint blockade (ICB) immunotherapy. In particular, piSTING can strengthen the impact of STING pathway in immunotherapy and accelerate the clinical translation of STING agonists. [ABSTRACT FROM AUTHOR]

DNA nanostructures have shown great potential in biomedical fields. However, the immune responses, especially the activation of the cGAS‐STING signaling (A‐cGSs), induced by DNA nanostructures, remain incompletely understood. Here, the ability of various DNA nanostructures from double‐stranded DNA (dsDNA), single‐stranded tiles (SSTs) to DNA origami is investigated on A‐cGSs. Unlike natural dsDNA which triggers potent A‐cGSs, the structural interconnectivity of various DNA configurations can substantially reduce the occurrence of A‐cGSs, irrespective of their form, dimensions, and conformation. However, wireframe DNA nanostructures can activate the cGAS‐STING signaling, suggesting that decreasing A‐cGSs is dsDNA compactness‐dependent. Based on this, a reconfigurable DNA Origami Domino Array (DODA) is used to systematically interrogate how dsDNA influences the A‐cGSs and demonstrates that the length, number, and space of dsDNA array coordinately influence the activation level of cGAS‐STING signaling, realizing a regulation of innate immune response. The above data and findings enhance the understanding of how DNA nanostructures affect cellular innate immune responses and new insights into the modulation of innate immune responses by DNA nanomedicine. [ABSTRACT FROM AUTHOR]

Alzheimer's disease and other tauopathies are characterized by the misfolding and aggregation of the tau protein into oligomeric and fibrillar structures. Antibodies against tau play an increasingly important role in studying these neurodegenerative diseases and the generation of tools to diagnose and treat them. The development of antibodies that recognize tau protein aggregates, however, is hindered by complex immunization and antibody selection strategies and limitations to antigen presentation. Here, we have taken a facile approach to identify single‐domain antibodies, or nanobodies, that bind to many forms of tau by screening a synthetic yeast surface display nanobody library against monomeric tau and creating multivalent versions of our lead nanobody, MT3.1, to increase its avidity for tau aggregates. We demonstrate that MT3.1 binds to tau monomer, oligomers, and fibrils, as well as pathogenic tau from a tauopathy mouse model, despite being identified through screens against monomeric tau. Through epitope mapping, we discovered binding epitopes of MT3.1 contain the key motif VQIXXK which drives tau aggregation. We show that our bivalent and tetravalent versions of MT3.1 have greatly improved binding ability to tau oligomers and fibrils compared to monovalent MT3.1. Our results demonstrate the utility of our nanobody screening and multivalent design approach in developing nanobodies that bind amyloidogenic protein aggregates. This approach can be extended to the generation of multivalent nanobodies that target other amyloid proteins and has the potential to advance the research and treatment of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Despite success in the treatment of some blood cancers and melanoma, positive response to immunotherapies remains disappointingly low in the treatment of solid tumors. The context of the molecular crosstalk within the tumor microenvironment can result in dysfunctional immune cell activation, leading to tumor tolerance and progression. Although modulating these protein–protein interactions (PPIs) is vital for appropriate immune cell activation and recognition, targeting nonenzymatic PPIs has proven to be fraught with challenges. To address this, a synthetic, multivalent molecular modality comprised of small interfering peptides precisely hybridized to a semirigid DNA scaffold is introduced. Herein, a prototype of this modality that targets the IL‐33/ST2 signaling axis, which is associated with tumor tolerance and immunotherapy treatment failure is described. Using peptides that mimic the specific high‐energy "hotspot" residues with which the IL‐33/ST2 coreceptor, IL‐1RAcP, interacts with the initial binary complex, this platform is shown to effectively bind IL‐33/ST2 with a KD of 110 nm. Additionally, this molecule effectively abrogates signal transduction in cell models at high nanomolar concentrations and is exquisitely selective for this complex over structurally similar PPIs within the same cytokine superfamily. [ABSTRACT FROM AUTHOR]

Biomolecular condensation, driven by multivalency, serves as a fundamental mechanism within cells, facilitating the formation of distinct compartments, including membraneless organelles that play essential roles in various cellular processes. Perturbations in the delicate equilibrium of condensation, whether resulting in gain or loss of phase separation, have robustly been associated with cellular dysfunction and physiological disorders. As ongoing research endeavors wholeheartedly embrace this newly acknowledged principle, a transformative shift is occurring in our comprehension of disease. Consequently, significant strides have been made in unraveling the profound relevance and potential causal connections between abnormal phase separation and various diseases. This comprehensive review presents compelling recent evidence that highlight the intricate associations between aberrant phase separation and neurodegenerative diseases, cancers, and infectious diseases. Additionally, we provide a succinct summary of current efforts and propose innovative solutions for the development of potential therapeutics to combat the pathological consequences attributed to aberrant phase separation. [ABSTRACT FROM AUTHOR]

Abstract Fibroblast growth factor receptor 1 (FGFR1) is a N-glycosylated cell surface receptor tyrosine kinase, which upon recognition of specific extracellular ligands, fibroblast growth factors (FGFs), initiates an intracellular signaling. FGFR1 signaling ensures homeostasis of cells by fine-tuning essential cellular processes, like differentiation, division, motility and death. FGFR1 activity is coordinated at multiple steps and unbalanced FGFR1 signaling contributes to developmental diseases and cancers. One of the crucial control mechanisms over FGFR1 signaling is receptor endocytosis, which allows for rapid targeting of FGF-activated FGFR1 to lysosomes for degradation and the signal termination. We have recently demonstrated that N-glycans of FGFR1 are recognized by a precise set of extracellular galectins, secreted and intracellular multivalent lectins implicated in a plethora of cellular processes and altered in immune responses and cancers. Specific galectins trigger FGFR1 clustering, resulting in activation of the receptor and in initiation of intracellular signaling cascades that shape the cell physiology. Although some of galectin family members emerged recently as key players in the clathrin-independent endocytosis of specific cargoes, their impact on endocytosis of FGFR1 was largely unknown. Here we assessed the contribution of extracellular galectins to the cellular uptake of FGFR1. We demonstrate that only galectin-1 induces internalization of FGFR1, whereas the majority of galectins predominantly inhibit endocytosis of the receptor. We focused on three representative galectins: galectin-1, -7 and -8 and we demonstrate that although all these galectins directly activate FGFR1 by the receptor crosslinking mechanism, they exert different effects on FGFR1 endocytosis. Galectin-1-mediated internalization of FGFR1 doesn’t require galectin-1 multivalency and occurs via clathrin-mediated endocytosis, resembling in this way the uptake of FGF/FGFR1 complex. In contrast galectin-7 and -8 impede FGFR1 endocytosis, causing stabilization of the receptor on the cell surface and prolonged propagation of the signals. Furthermore, using protein engineering approaches we demonstrate that it is possible to modulate or even fully reverse the endocytic potential of galectins.

Vaccines are among the most cost-effective public health measures for controlling infectious diseases. Coxiella burnetii is the etiological agent of Q fever, a disease with a wide clinical spectrum that ranges from mild symptoms, such as fever and fatigue, to more severe disease, such as pneumonia and endocarditis. The formalin-inactivated whole-cell vaccine Q-VAX® contains hundreds of antigens and confers lifelong protection in humans, but prior sensitization from infection or vaccination can result in deleterious reactogenic responses to vaccination. Consequently, there is great interest in developing non-reactogenic alternatives based on adjuvanted recombinant proteins. In this study, we aimed to develop a multivalent vaccine that conferred protection with reduced reactogenicity. We hypothesized that a multivalent vaccine consisting of multiple antigens would be more immunogenic and protective than a monovalent vaccine owing to the large number of potential protective antigens in the C. burnetii proteome. To address this, we identified immunogenic T and B cell antigens, and selected proteins were purified to evaluate with a combination adjuvant (IVAX-1), with or without C. burnetii lipopolysaccharide (LPS) in immunogenicity studies in vivo in mice and in a Hartley guinea pig intratracheal aerosol challenge model using C. burnetii strain NMI RSA 493. The data showed that multivalent vaccines are more immunogenic than monovalent vaccines and more closely emulate the protection achieved by Q-VAX. Although six antigens were the most immunogenic, we also discovered that multiplexing beyond four antigens introduces detectable reactogenicity, indicating that there is an upper limit to the number of antigens that can be safely included in a multivalent Q-fever vaccine. C. burnetii LPS also demonstrates efficacy as a vaccine antigen in conferring protection in an otherwise monovalent vaccine formulation, suggesting that its addition in multivalent vaccines, as demonstrated by a quadrivalent formulation, would improve protective responses.

Nanobioconjugates are extensively employed in an array of biomedical applications, such as photodynamic therapy materials, drug delivery carriers, bioimaging probes, single molecule tracking, detection probes, and brain targeting agents through transcytosis. To provide these biological applications, nanoparticles need to be designed delicately with specific targeting ligands to recognize specific molecules or to target specific receptors over the cell's surface, and this cellular internalization process generally follows a receptor-mediated endocytosis pathway. The variables that govern this interaction as well as the cellular entry/exit process are the size and shape of the nanoparticle, surface chemistry and surface charge of the nanoparticle, and nanoparticle multivalency (the number of targeting ligands on the nanoparticle surface). Herein, we elaborately discuss the nanoparticle multivalency parameter. Monovalent nanobioconjugates always interact with cell receptors through 1:1 interaction and reduce receptor clustering, which is inefficient for nanoparticle internalization. In the case of multivalent nanobioconjugates, this interaction occurs through multiple ligands from one nanoparticle with multiple receptors on the cell surface, which leads to receptor clustering. However, nanobioconjugates with uncontrolled multivalency reduce receptor mobility, followed by lysosomal trapping, and fail for proper biomedical applications. Therefore, the development of nanobioconjugates with modular or controlled multivalency is much more challenging and is also needed for different biomedical applications. Throughout this review, we describe the crucial role of nanoparticle multivalency in different biomedical applications. Next, we discuss various synthesis approaches to develop monovalent nanobioconjugates via a surface masking strategy and streptavidin–biotin interaction. Moreover, we discuss how nanoparticle multivalency can be controlled by using a competitor of targeting ligand, by regulating the size of the nanoparticle, and by changing the reaction medium/reaction condition. Next, we demonstrate how nanoparticle multivalency directs the cellular entry–exit mechanism, subcellular targeting, and brain targeting. Finally, we discuss the application and effect of multivalent nanobioconjugates in drug delivery, tumor targeting, single-molecule imaging, and detection of cancer cells/proteins/peptides. [ABSTRACT FROM AUTHOR]

Fibroblast growth factors (FGFs) and their receptors (FGFRs) constitute plasma-membrane localized signaling hubs that transmit signals from the extracellular environment to the cell interior, governing pivotal cellular processes like motility, metabolism, differentiation, division and death. FGF/FGFR signaling is critical for human body development and homeostasis; dysregulation of FGF/FGFR units is observed in numerous developmental diseases and in about 10% of human cancers. Glycosylation is a highly abundant posttranslational modification that is critical for physiological and pathological functions of the cell. Glycosylation is also very common within FGF/FGFR signaling hubs. Vast majority of FGFs (15 out of 22 members) are N-glycosylated and few FGFs are O-glycosylated. Glycosylation is even more abundant within FGFRs; all FGFRs are heavily N-glycosylated in numerous positions within their extracellular domains. A growing number of studies points on the multiple roles of glycosylation in fine-tuning FGF/FGFR signaling. Glycosylation modifies secretion of FGFs, determines their stability and affects interaction with FGFRs and co-receptors. Glycosylation of FGFRs determines their intracellular sorting, constitutes autoinhibitory mechanism within FGFRs and adjusts FGF and co-receptor recognition. Sugar chains attached to FGFs and FGFRs constitute also a form of code that is differentially decrypted by extracellular lectins, galectins, which transform FGF/FGFR signaling at multiple levels. This review focuses on the identified functions of glycosylation within FGFs and FGFRs and discusses their relevance for the cell physiology in health and disease. [Display omitted] • FGF/FGFR signaling plays a pivotal role in establishing and maintaining the cell and organism homeostasis. • Vast majority of FGF proteins and all FGFRs are N-glycosylated. • N- and O-glycosylation of FGFs affects their secretion, stability and function. • N-glycosylation of FGFRs facilitates intracellular trafficking of FGFRs to the cell surface and regulates FGFRs interaction with FGFs and co-receptors. • N-glycosylation of FGFs and FGFRs constitutes a layer of information differentially read by galectins and transformed into specific modulatory activities. [ABSTRACT FROM AUTHOR]

The Eurasian Iron Age Scythians, in all their regional iterations, are known for their lavish burials found in various kinds of tumuli. These tumuli, of varying sizes, are located throughout the Eurasian steppe. Based, at least partially, on the amounts and types of grave goods found within these mounds, the Scythians are usually modeled as militant, patriarchal mobile pastoralists, with rigid social structures. Yet, such interpretations are also due to accounts of Scythian lifeways provided by "classical" societies from the Greeks to the Persians, who saw the Scythians largely as barbarians, much like their neighbors to the north of the Greeks, the "Celts". Despite recent interrogations of the barbarian trope, and the opportunity to dissect the classic formula of large mounds = elevated status, I contend that many studies on Scythian mortuary practices remain monolithic and under-theorized, especially by Western scholars. Drawing upon different conceptual and methodological frameworks, I present alternative, multi-scalar understandings of Scythian mortuary landscapes. Utilizing a spacetime-oriented, dialogical approach supplemented with geographic information systems, I interrogate how and why various meanings and experiences may have intersected in these protean Scythian landscapes of the dead, rather than reducing them to monolithic symbolic proxies of ideological status. [ABSTRACT FROM AUTHOR]

Fibroblast growth factor receptor 1 (FGFR1) is a N-glycosylated cell surface receptor tyrosine kinase, which upon recognition of specific extracellular ligands, fibroblast growth factors (FGFs), initiates an intracellular signaling. FGFR1 signaling ensures homeostasis of cells by fine-tuning essential cellular processes, like differentiation, division, motility and death. FGFR1 activity is coordinated at multiple steps and unbalanced FGFR1 signaling contributes to developmental diseases and cancers. One of the crucial control mechanisms over FGFR1 signaling is receptor endocytosis, which allows for rapid targeting of FGF-activated FGFR1 to lysosomes for degradation and the signal termination. We have recently demonstrated that N-glycans of FGFR1 are recognized by a precise set of extracellular galectins, secreted and intracellular multivalent lectins implicated in a plethora of cellular processes and altered in immune responses and cancers. Specific galectins trigger FGFR1 clustering, resulting in activation of the receptor and in initiation of intracellular signaling cascades that shape the cell physiology. Although some of galectin family members emerged recently as key players in the clathrin-independent endocytosis of specific cargoes, their impact on endocytosis of FGFR1 was largely unknown. Here we assessed the contribution of extracellular galectins to the cellular uptake of FGFR1. We demonstrate that only galectin-1 induces internalization of FGFR1, whereas the majority of galectins predominantly inhibit endocytosis of the receptor. We focused on three representative galectins: galectin-1, -7 and -8 and we demonstrate that although all these galectins directly activate FGFR1 by the receptor crosslinking mechanism, they exert different effects on FGFR1 endocytosis. Galectin-1-mediated internalization of FGFR1 doesn't require galectin-1 multivalency and occurs via clathrin-mediated endocytosis, resembling in this way the uptake of FGF/FGFR1 complex. In contrast galectin-7 and -8 impede FGFR1 endocytosis, causing stabilization of the receptor on the cell surface and prolonged propagation of the signals. Furthermore, using protein engineering approaches we demonstrate that it is possible to modulate or even fully reverse the endocytic potential of galectins. [ABSTRACT FROM AUTHOR]

Selective protein degradation platforms have opened novel avenues in therapeutic development and biological inquiry. Antibody‐based lysosome‐targeting chimeras (LYTACs) have emerged as a promising technology that extends the scope of targeted protein degradation to extracellular targets. Aptamers offer an advantageous alternative owing to their potential for modification and manipulation toward a multivalent state. In this study, a chemically engineered platform of multivalent aptamer‐based LYTACs (AptLYTACs) is established for the targeted degradation of either single or dual protein targets. Leveraging the biotin‐streptavidin system as a molecular scaffold, this investigation reveals that trivalently mono‐targeted AptLYTACs demonstrate optimum efficiency in degrading membrane proteins. The development of this multivalent AptLYTACs platform provides a principle of concept for mono‐/dual‐targets degradation, expanding the possibilities of targeted protein degradation. [ABSTRACT FROM AUTHOR]

Multivalency represents an appealing option to modulate selectivity in enzyme inhibition and transform moderate glycosidase inhibitors into highly potent ones. The rational design of multivalent inhibitors is however challenging because global affinity enhancement relies on several interconnected local mechanistic events, whose relative impact is unknown. So far, the largest multivalent effects ever reported for a non‐polymeric glycosidase inhibitor have been obtained with cyclopeptoid‐based inhibitors of Jack bean α‐mannosidase (JBα‐man). Here, we report a structure‐activity relationship (SAR) study based on the top‐down deconstruction of best‐in‐class multivalent inhibitors. This approach provides a valuable tool to understand the complex interdependent mechanisms underpinning the inhibitory multivalent effect. Combining SAR experiments, binding stoichiometry assessments, thermodynamic modelling and atomistic simulations allowed us to establish the significant contribution of statistical rebinding mechanisms and the importance of several key parameters, including inhitope accessibility, topological restrictions, and electrostatic interactions. Our findings indicate that strong chelate‐binding, resulting from the formation of a cross‐linked complex between a multivalent inhibitor and two dimeric JBα‐man molecules, is not a sufficient condition to reach high levels of affinity enhancements. The deconstruction approach thus offers unique opportunities to better understand multivalent binding and provides important guidelines for the design of potent and selective multiheaded inhibitors. [ABSTRACT FROM AUTHOR]

Enveloped viruses carry one or multiple proteins with receptor‐binding functionalities. Functional receptors can be glycans, proteinaceous, or both; therefore, recombinant protein approaches are instrumental in attaining new insights regarding viral envelope protein receptor‐binding properties. Visualizing and measuring receptor binding typically entails antibody detection or direct labeling, whereas direct fluorescent fusions are attractive tools in molecular biology. Here, we report a suite of distinct fluorescent fusions, both N‐ and C‐terminal, for influenza A virus hemagglutinins and SARS‐CoV‐2 spike RBD. The proteins contained three or six fluorescent protein barrels and were applied directly to cells to assess receptor binding properties. [ABSTRACT FROM AUTHOR]

Despite success in the treatment of some blood cancers and melanoma, positive response to immunotherapies remains disappointingly low in the treatment of solid tumors. The context of the molecular crosstalk within the tumor microenvironment can result in dysfunctional immune cell activation, leading to tumor tolerance and progression. Although modulating these protein–protein interactions (PPIs) is vital for appropriate immune cell activation and recognition, targeting nonenzymatic PPIs has proven to be fraught with challenges. To address this, a synthetic, multivalent molecular modality comprised of small interfering peptides precisely hybridized to a semirigid DNA scaffold is introduced. Herein, a prototype of this modality that targets the IL‐33/ST2 signaling axis, which is associated with tumor tolerance and immunotherapy treatment failure is described. Using peptides that mimic the specific high‐energy “hotspot” residues with which the IL‐33/ST2 coreceptor, IL‐1RAcP, interacts with the initial binary complex, this platform is shown to effectively bind IL‐33/ST2 with a KD of 110 nm. Additionally, this molecule effectively abrogates signal transduction in cell models at high nanomolar concentrations and is exquisitely selective for this complex over structurally similar PPIs within the same cytokine superfamily.

Sodium–glucose co-transporter 1 (SGLT1) and sodium-dependent neutral amino acid transporter (B0AT1) are mainly expressed on the membrane of enterocytes, a type of epithelial cell found in the intestines. In addition to their physiological role in the absorption of nutrients, a protective role in the integrity of the intestinal barrier has been established. The natural ligands of SGLT1 (d-glucose) and of B0AT1 (l-glutamine) can trigger a protective anti-inflammatory effect on the intestinal epithelium. The literature suggests the activation of common intracellular pathways upon engagement of the two transporters, whose functional forms are composed of oligomers or clusters. Simultaneous activation of these two co-transporters could lead to a potential multitarget and synergistic anti-inflammatory effect. Therefore, nanoplatforms containing multiple copies of the ligands could represent chemical tools to study the potential simultaneous activation of the two co-transporters. For these reasons, in this study, a set of different gold nanoparticles decorated with derivatives of d-glucose and of l-glutamine were designed and prepared. In particular, the synthesis of suitable sulfur-ending functionalized ligand derivatives, including a C-glucoside derivative, their anchoring to gold nanoparticles and their physical–chemical characterization have been carried out. The obtained nanostructures could represent promising multifunctional platforms for further investigation of the existence of possible multitarget and synergistic effects toward the two co-transporters SGLT1 and B0AT1. [ABSTRACT FROM AUTHOR]

The interactions of glycosaminoglycans (GAG) with proteins of the extracellular matrix govern and regulate complex physiological functions including cellular growth, immune response, and inflammation. Repetitive presentation of GAG binding motifs, as found in native proteoglycans, might enhance GAG‐protein binding through multivalent interactions. Here, we report the chemical synthesis of dendritic GAG oligomers constructed of nonasulfated hyaluronan tetrasaccharides for investigating the binding of the protein chemokine interleukin 8 (IL‐8) to artificial, well‐defined proteoglycan architectures. Binding of mutant monomeric and native dimerizable IL‐8 was investigated by NMR spectroscopy and isothermal titration calorimetry. Dendritic oligomerization of GAG increased the binding affinity of both monomeric and dimeric IL‐8. Monomeric IL‐8 bound to monomeric and dimeric GAG with KD values of 7.3 and 0.108 μM, respectively. The effect was less pronounced for dimerizable wild‐type IL‐8, for which GAG dimerization improved the affinity from 34 to 5 nM. Binding of dimeric IL‐8 to oligomeric GAG was limited by steric crowding effects, strongly reducing the affinity of subsequent binding events. In conclusion, the strongest effect of GAG oligomerization was the amplified binding of IL‐8 monomers, which might concentrate monomeric protein in the extracellular matrix and thus promote protein dimerization under physiological conditions. [ABSTRACT FROM AUTHOR]

Intravitreal (IVT) injection of anti-vascular endothelial growth factor (anti-VEGF) has greatly improved the treatment of many retinal disorders, including wet age-related macular degeneration (wAMD), which is the third leading cause of blindness. However, frequent injections can be difficult for patients and may lead to various risks such as elevated intraocular pressure, infection, and retinal detachment. To address this issue, researchers have found that IVT injection of anti-VEGF proteins at their maximally viable concentration and dose can be an effective strategy. However, the intrinsic protein structure can limit the maximum concentration due to stability and solution viscosity. To overcome this challenge, we developed a novel anti-VEGF protein called nanoFc by fusing anti-VEGF nanobodies with a crystallizable fragment (Fc). NanoFc has demonstrated high binding affinity to VEGF165 through multivalency and potent bioactivity in various bioassays. Furthermore, nanoFc maintains satisfactory chemical and physical stability at 4°C over 1 month and is easily injectable at concentrations up to 200 mg/mL due to its unique architecture that yields a smaller shape factor. The design of nanoFc offers a bioengineering strategy to ensure both strong anti-VEGF binding affinity and high protein concentration, with the goal of reducing the frequency of IV injections. [ABSTRACT FROM AUTHOR]

The "carbohydrate chemical mimicry" exhibited by sp2‐iminosugars has been utilized to develop practical syntheses for analogs of the branched high‐mannose‐type oligosaccharides (HMOs) Man3 and Man5. In these compounds, the terminal nonreducing Man residues have been substituted with 5,6‐oxomethylidenemannonojirimycin (OMJ) motifs. The resulting oligomannoside hemimimetic accurately reproduce the structure, configuration, and conformational behavior of the original mannooligosaccharides, as confirmed by NMR and computational techniques. Binding studies with mannose binding lectins, including concanavalin A, DC‐SIGN, and langerin, by enzyme‐linked lectin assay and surface plasmon resonance revealed significant variations in their ability to accommodate the OMJ unit in the mannose binding site. Intriguingly, OMJMan segments demonstrated "in line" heteromultivalent effects during binding to the three lectins. Similar to the mannobiose (Man2) branches in HMOs, the binding modes involving the external or internal monosaccharide unit at the carbohydrate binding‐domain exist in equilibrium, facilitating sliding and recapture processes. This equilibrium, which influences the multivalent binding of HMOs, can be finely modulated upon incorporation of the OMJ sp2‐iminosugar caps. As a proof of concept, the affinity and selectivity towards DC‐SIGN and langerin were adjustable by presenting the OMJMan epitope in platforms with diverse architectures and valencies. [ABSTRACT FROM AUTHOR]

Microtubules are cytoskeletal polymers that play important roles in numerous cellular processes, ranging from the control of cell shape and polarity to cell division and intracellular transport. Many of these roles rely on proteins that bind to microtubule ends and shafts, carry intrinsically disordered regions, and form complex multivalent interaction networks. A flurry of recent studies demonstrated that these properties allow diverse microtubule-binding proteins to undergo liquid–liquid phase separation (LLPS) in vitro. It is proposed that LLPS could potentially affect multiple microtubule-related processes, such as microtubule nucleation, control of microtubule dynamics and organization, and microtubule-based transport. Here, we discuss the evidence in favor and against the occurrence of LLPS and its functional significance for microtubule-based processes in cells. Liquid–liquid phase separation (LLPS) is a common phenomenon observed for microtubule-binding proteins expressed recombinantly in vitro , or overexpressed in cells. LLPS of microtubule-binding proteins in vitro can be driven by very different types of interactions, involving intrinsically disordered regions and folded domains. Binding to microtubules can promote formation of protein condensates. Condensates of tubulin-binding proteins can potentially promote microtubule nucleation and accelerate microtubule elongation. Condensate formation by the same or homologous proteins strongly depends on the species, cell type, or cell cycle phase. Conclusive evidence that LLPS occurs at physiological conditions in cells is often missing. [ABSTRACT FROM AUTHOR]

Abstract Selective protein degradation platforms have opened novel avenues in therapeutic development and biological inquiry. Antibody‐based lysosome‐targeting chimeras (LYTACs) have emerged as a promising technology that extends the scope of targeted protein degradation to extracellular targets. Aptamers offer an advantageous alternative owing to their potential for modification and manipulation toward a multivalent state. In this study, a chemically engineered platform of multivalent aptamer‐based LYTACs (AptLYTACs) is established for the targeted degradation of either single or dual protein targets. Leveraging the biotin‐streptavidin system as a molecular scaffold, this investigation reveals that trivalently mono‐targeted AptLYTACs demonstrate optimum efficiency in degrading membrane proteins. The development of this multivalent AptLYTACs platform provides a principle of concept for mono‐/dual‐targets degradation, expanding the possibilities of targeted protein degradation.

Chem. 2009, 7: 2013 57 The term "inhitope" was coined in 2013, see: Rísquez-Cuadro, R. García Fernández, J M. Nierengarten, J.-F. Ortiz Mellet, C. Chem. Eur. J. 2013, 19: 16791 58 Lepage, M L. Mirloup, A. Ripoll, M. Stauffert, F. Bodlenner, A. Ziessel, R. Compain, P. Belstein J. Org. Keywords: glycomimetics; multivalency; enzyme inhibitors; synthetic methodologies; carbohydrates EN glycomimetics multivalency enzyme inhibitors synthetic methodologies carbohydrates 1866 1893 28 09/15/23 20231004 NES 231004 Graph 1 Introduction In a previous Account article, [1] written in Fall 2013 following the invitation of Prof. K. Peter C. Vollhardt, I stated that " I the field of glycomimetics is a fantastic playground for a synthetic chemist interested in biology i ." 2014, 15: 1239 51 Gouin, S G. Chem. Eur. J. 2014, 20: 11616 52 Zelli, R. Longevial, J.- F. Dumy, P. Marra, A. New J. Chem. 2015, 30: 5050 53 Matassini, C. Parmeggiani, C. Cardona, F. Goti, A. Tetrahedron Lett. 2017, 4: 2500 40 Espino, C G. Wehn, P M. Chow, J. Du Bois, J. J. Am. Chem. Soc. 2001, 123: 6935 41 Roizen, J L. Harvey, M E. Du Bois, J. Acc. Chem. 2003, 59: 2693 46 Iehl, J. Nierengarten, J.-F. Chem. Eur. J. 2009, 15: 7306 47 Compain, P. Chem. Rec. 2020, 20: 10 48 Compain, P. Decroocq, C. Iehl, J. Holler, M. Hazelard, D. Mena Barragán, T. Ortiz Mellet, C. Nierengarten, J.-F. Angew. [Extracted from the article]

This article explores the conversation between Jesus and Nicodemus in John 3:1–21, highlighting the ways omissions, multivalency, and intratextual and intertextual links invite audience participation and encourage listeners to see themselves as re-generated children of God. In this way, persuaded audiences assent not just to the content of the Gospel, but to its epistemology—how it instructs them to receive and seek truth. As classical and contemporary rhetorical theories indicate, when audiences participate to create the world of the Gospel, they are more likely to be persuaded by it and to use it to craft the reality in which they live. [ABSTRACT FROM AUTHOR]

Abstract Fibroblast growth factors (FGFs) and their receptors (FGFRs) constitute complex signaling hubs that are crucial for the development and homeostasis of the human body. Most of FGFs are released by cells using the conventional secretory pathway and are N-glycosylated, yet the role of FGFs glycosylation is largely unknown. Here, we identify N-glycans of FGFs as binding sites for a specific set of extracellular lectins, galectins − 1, -3, -7 and − 8. We demonstrate that galectins attract N-glycosylated FGF4 to the cell surface, forming a reservoir of the growth factor in the extracellular matrix. Furthermore, we show that distinct galectins differentially modulate FGF4 signaling and FGF4-dependent cellular processes. Using engineered variants of galectins with altered valency we demonstrate that multivalency of galectins is critical for the adjustment of FGF4 activity. Summarizing, our data reveal a novel regulatory module within FGF signaling, in which the glyco-code in FGFs provides previously unanticipated information differentially deciphered by multivalent galectins, affecting signal transduction and cell physiology. Video Abstract

The Eurasian Iron Age Scythians, in all their regional iterations, are known for their lavish burials found in various kinds of tumuli. These tumuli, of varying sizes, are located throughout the Eurasian steppe. Based, at least partially, on the amounts and types of grave goods found within these mounds, the Scythians are usually modeled as militant, patriarchal mobile pastoralists, with rigid social structures. Yet, such interpretations are also due to accounts of Scythian lifeways provided by “classical” societies from the Greeks to the Persians, who saw the Scythians largely as barbarians, much like their neighbors to the north of the Greeks, the “Celts”. Despite recent interrogations of the barbarian trope, and the opportunity to dissect the classic formula of large mounds = elevated status, I contend that many studies on Scythian mortuary practices remain monolithic and under-theorized, especially by Western scholars. Drawing upon different conceptual and methodological frameworks, I present alternative, multi-scalar understandings of Scythian mortuary landscapes. Utilizing a spacetime-oriented, dialogical approach supplemented with geographic information systems, I interrogate how and why various meanings and experiences may have intersected in these protean Scythian landscapes of the dead, rather than reducing them to monolithic symbolic proxies of ideological status.

To minimize the incorrect use of antibiotics, there is a great need for rapid and inexpensive tests to identify the pathogens that cause an infection. The gold standard of pathogen identification is based on the recognition of DNA sequences that are unique for a given pathogen. Here, we propose and test a strategy to develop simple, fast, and highly sensitive biosensors that make use of multivalency. Our approach uses DNA-functionalized polystyrene colloids that distinguish pathogens on the basis of the frequency of selected short DNA sequences in their genome. Importantly, our method uses entire genomes and does not require nucleic acid amplification. Polystyrene colloids grafted with specially designed surface DNA probes can bind cooperatively to frequently repeated sequences along the entire genome of the target bacteria, resulting in the formation of large and easily detectable colloidal aggregates. Our detection strategy allows "mix and read" detection of the target analyte; it is robust and highly sensitive over a wide concentration range covering, in the case of our test target genome Escherichia coli bl21-de3, 10 orders of magnitude from 101 to 1010 copies/mL. The sensitivity compares well with state-of-the-art sensing techniques and has excellent specificity against nontarget bacteria. When applied to real samples, the proposed technique shows an excellent recovery rate. Our detection strategy opens the way to developing a robust platform for pathogen detection in the fields of food safety, disease control, and environmental monitoring. [ABSTRACT FROM AUTHOR]

Phase-separated condensates can act as activation platforms for kinases that can sense the molecular features of condensates (e.g., polyubiquitin). Liquid–liquid phase separation (LLPS) compartmentalizes kinases, substrates, and cofactors to promote substrate selectivity and spatiotemporal control of signaling events. Some kinases can act as scaffolds for phase separation, whereas others act as clients that depend on the LLPS properties of scaffolds. Tyrosine phosphorylation can initiate LLPS by recruiting SH2 domain-containing proteins, which in turn recruit other proteins into the forming condensate. Oncogenic kinase fusions often include oligomerization domains and intrinsically disordered regions of the fusion partner, which may promote LLPS-mediated activation of the kinase fusion. Liquid–liquid phase separation (LLPS) is emerging as a mechanism of spatiotemporal regulation that could answer long-standing questions about how order is achieved in biochemical signaling. In this review we discuss how LLPS orchestrates kinase signaling, either by creating condensate structures that are sensed by kinases or by direct LLPS of kinases, cofactors, and substrates – thereby acting as a mechanism to compartmentalize kinase–substrate relationships, and in some cases also sequestering the kinase away from inhibitory factors. We also examine the possibility that selective pressure promotes genomic rearrangements that fuse pro-growth kinases to LLPS-prone protein sequences, which in turn drives aberrant kinase activation through LLPS. [ABSTRACT FROM AUTHOR]

The development of subunit vaccine platforms has been of considerable interest due to their good safety profile and ability to be adapted to new antigens, compared to other vaccine typess. Nevertheless, subunit vaccines often lack sufficient immunogenicity to fully protect against infectious diseases. A wide variety of subunit vaccines have been developed to enhance antigen immunogenicity by increasing antigen multivalency, as well as stability and delivery properties, via presentation of antigens on protein nanoparticles. Increasing multivalency can be an effective approach to provide a potent humoral immune response by more strongly engaging and clustering B cell receptors (BCRs) to induce activation, as well as increased uptake by antigen presenting cells and their subsequent T cell activation. Proper orientation of antigen on protein nanoparticles is also considered a crucial factor for enhanced BCR engagement and subsequent immune responses. Therefore, various strategies have been reported to decorate highly repetitive surfaces of protein nanoparticle scaffolds with multiple copies of antigens, arrange antigens in proper orientation, or combinations thereof. In this review, we describe different chemical bioconjugation methods, approaches for genetic fusion of recombinant antigens, biological affinity tags, and enzymatic conjugation methods to effectively present antigens on the surface of protein nanoparticle vaccine scaffolds. [ABSTRACT FROM AUTHOR]

Short peptides are poor immunogens. One way to increase their immune responses is by arraying immunogens in multivalency. Simple and efficient scaffolds for spatial controlling the inter-antigen distance and enhancing immune activation are required. Here, we report a molecular vaccine design principle that maximally drives potent SARS-CoV-2 RBD subunit vaccine on DNA duplex to induce robust and efficacious immune responses in vivo. We expect that the DNA–peptide epitope platform represents a facile and generalizable strategy to enhance the immune response. DNA scaffolds offer a biocompatible and convenient platform for arraying immunogens in multivalency antigenic peptides, and spatially control the inter-antigen distance. This can effectively enhance immune response. Peptide (instead of entire protein) vaccines are highly attractive. However, short peptides are poor immunogens. Our DNA scaffolded multivalent peptide immunogen system induced robust and efficacious immune response in vivo as demonstrated by the antigenic peptide against SARS-CoV-2. The present strategy could be readily generalized and adapted to prepare multivalent vaccines against other viruses or disease. Particularly, the different antigens could be integrated into one single vaccine and lead to super-vaccines that can protect the host from multiple different viruses or multiple variants of the same virus. [Display omitted] [ABSTRACT FROM AUTHOR]

Fibroblast growth factors (FGFs) and their receptors (FGFRs) constitute complex signaling hubs that are crucial for the development and homeostasis of the human body. Most of FGFs are released by cells using the conventional secretory pathway and are N-glycosylated, yet the role of FGFs glycosylation is largely unknown. Here, we identify N-glycans of FGFs as binding sites for a specific set of extracellular lectins, galectins − 1, -3, -7 and − 8. We demonstrate that galectins attract N-glycosylated FGF4 to the cell surface, forming a reservoir of the growth factor in the extracellular matrix. Furthermore, we show that distinct galectins differentially modulate FGF4 signaling and FGF4-dependent cellular processes. Using engineered variants of galectins with altered valency we demonstrate that multivalency of galectins is critical for the adjustment of FGF4 activity. Summarizing, our data reveal a novel regulatory module within FGF signaling, in which the glyco-code in FGFs provides previously unanticipated information differentially deciphered by multivalent galectins, affecting signal transduction and cell physiology. 8PPE1YWgWFxc_zmTSXi8tA Video Abstract [ABSTRACT FROM AUTHOR]

Galectins are carbohydrate-binding lectins that modulate the proliferation, apoptosis, adhesion, or migration of cells by cross-linking glycans on cell membranes or extracellular matrix components. Galectin-4 (Gal-4) is a tandem-repeat-type galectin expressed mainly in the epithelial cells of the gastrointestinal tract. It consists of an N- and a C-terminal carbohydrate-binding domain (CRD), each with distinct binding affinities, interconnected with a peptide linker. Compared to other more abundant galectins, the knowledge of the pathophysiology of Gal-4 is sparse. Its altered expression in tumor tissue is associated with, for example, colon, colorectal, and liver cancers, and it increases in tumor progression, and metastasis. There is also very limited information on the preferences of Gal-4 for its carbohydrate ligands, particularly with respect to Gal-4 subunits. Similarly, there is virtually no information on the interaction of Gal-4 with multivalent ligands. This work shows the expression and purification of Gal-4 and its subunits and presents a structure–affinity relationship study with a library of oligosaccharide ligands. Furthermore, the influence of multivalency is demonstrated in the interaction with a model lactosyl-decorated synthetic glycoconjugate. The present data may be used in biomedical research for the design of efficient ligands of Gal-4 with diagnostic or therapeutic potential. [ABSTRACT FROM AUTHOR]

FGF/FGFR signaling is critical for the development and homeostasis of the human body and imbalanced FGF/FGFR contributes to the progression of severe diseases, including cancers. FGFRs are N-glycosylated, but the role of these modifications is largely unknown. Galectins are extracellular carbohydrate-binding proteins implicated in a plethora of processes in heathy and malignant cells. Here, we identified a precise set of galectins (galectin-1, -3, -7, and -8) that directly interact with N-glycans of FGFRs. We demonstrated that galectins bind N-glycan chains of the membrane-proximal D3 domain of FGFR1 and trigger differential clustering of FGFR1, resulting in activation of the receptor and initiation of downstream signaling cascades. Using engineered galectins with controlled valency, we provide evidence that N-glycosylation-dependent clustering of FGFR1 constitutes a mechanism for FGFR1 stimulation by galectins. We revealed that the consequences of galectin/FGFR signaling for cell physiology are markedly different from the effects induced by canonical FGF/FGFR units, with galectin/FGFR signaling affecting cell viability and metabolic activity. Furthermore, we showed that galectins are capable of activating an FGFR pool inaccessible for FGF1, enhancing the amplitude of transduced signals. Summarizing, our data identify a novel mechanism of FGFR activation, in which the information stored in the N-glycans of FGFRs provides previously unanticipated information about FGFRs’ spatial distribution, which is differentially deciphered by distinct multivalent galectins, affecting signal transmission and cell fate. [ABSTRACT FROM AUTHOR]

Vaccines are among the most cost-effective public health measures for controlling infectious diseases. Coxiella burnetii is the etiological agent of Q fever, a disease with a wide clinical spectrum that ranges from mild symptoms, such as fever and fatigue, to more severe disease, such as pneumonia and endocarditis. The formalin-inactivated whole-cell vaccine Q-VAX® contains hundreds of antigens and confers lifelong protection in humans, but prior sensitization from infection or vaccination can result in deleterious reactogenic responses to vaccination. Consequently, there is great interest in developing non-reactogenic alternatives based on adjuvanted recombinant proteins. In this study, we aimed to develop a multivalent vaccine that conferred protection with reduced reactogenicity. We hypothesized that a multivalent vaccine consisting of multiple antigens would be more immunogenic and protective than a monovalent vaccine owing to the large number of potential protective antigens in the C. burnetii proteome. To address this, we identified immunogenic T and B cell antigens, and selected proteins were purified to evaluate with a combination adjuvant (IVAX-1), with or without C. burnetii lipopolysaccharide (LPS) in immunogenicity studies in vivo in mice and in a Hartley guinea pig intratracheal aerosol challenge model using C. burnetii strain NMI RSA 493. The data showed that multivalent vaccines are more immunogenic than monovalent vaccines and more closely emulate the protection achieved by Q-VAX. Although six antigens were the most immunogenic, we also discovered that multiplexing beyond four antigens introduces detectable reactogenicity, indicating that there is an upper limit to the number of antigens that can be safely included in a multivalent Q-fever vaccine. C. burnetii LPS also demonstrates efficacy as a vaccine antigen in conferring protection in an otherwise monovalent vaccine formulation, suggesting that its addition in multivalent vaccines, as demonstrated by a quadrivalent formulation, would improve protective responses.

Sodium–glucose co-transporter 1 (SGLT1) and sodium-dependent neutral amino acid transporter (B0AT1) are mainly expressed on the membrane of enterocytes, a type of epithelial cell found in the intestines. In addition to their physiological role in the absorption of nutrients, a protective role in the integrity of the intestinal barrier has been established. The natural ligands of SGLT1 (d-glucose) and of B0AT1 (l-glutamine) can trigger a protective anti-inflammatory effect on the intestinal epithelium. The literature suggests the activation of common intracellular pathways upon engagement of the two transporters, whose functional forms are composed of oligomers or clusters. Simultaneous activation of these two co-transporters could lead to a potential multitarget and synergistic anti-inflammatory effect. Therefore, nanoplatforms containing multiple copies of the ligands could represent chemical tools to study the potential simultaneous activation of the two co-transporters. For these reasons, in this study, a set of different gold nanoparticles decorated with derivatives of d-glucose and of l-glutamine were designed and prepared. In particular, the synthesis of suitable sulfur-ending functionalized ligand derivatives, including a C-glucoside derivative, their anchoring to gold nanoparticles and their physical–chemical characterization have been carried out. The obtained nanostructures could represent promising multifunctional platforms for further investigation of the existence of possible multitarget and synergistic effects toward the two co-transporters SGLT1 and B0AT1.

The occurrence and spreading of multidrug resistance in bacterial pathogens represent one of the greatest challenges of the 21st century. With fewer and fewer new antibiotics in development, novel and unconventional concepts in drug development and formulation need to be explored to overcome the global antibiotics crisis. Biomedical nanotechnology offers promising strategies for the reformulation of established antibiotics in such a way that they regain their activity against resistant pathogens. Herein, promising developments aimed at the synthesis of potent nanoparticle‐based formulations of glycopeptide antibiotics are reviewed. While glycopeptide antibiotics such as vancomycin and teicoplanin are widely used as drugs of last resort against Gram‐positive pathogens such as methicillin‐resistant Staphylococcus aureus (MRSA), bacterial resistance against these drugs is spreading. However, inhibiting cell wall synthesis via binding to cell wall precursor peptidoglycans, glycopeptide antibiotics exhibit a unique mode of action that renders them particularly promising candidates for nanoparticle‐based formulations with the ability to overcome glycopeptide antibiotic resistance. Herein, different formulation concepts based on multivalent presentation and encapsulation are introduced, different synthesis and conjugation strategies are discussed, and an attempt is made to rationalize their effects on the antibacterial activity of the resulting nanoparticle formulations.

LC8, a ubiquitous and highly conserved hub protein, binds over 100 proteins involved in numerous cellular functions, including cell death, signaling, tumor suppression, and viral infection. LC8 binds intrinsically disordered proteins (IDPs), and although several of these contain multiple LC8 binding motifs, the effects of multivalency on complex formation are unclear. Drosophila ASCIZ has seven motifs that vary in sequence and inter-motif linker lengths, especially within subdomain QT2–4 containing the second, third, and fourth LC8 motifs. Using isothermal-titration calorimetry, analytical-ultracentrifugation, and native mass-spectrometry of QT2–4 variants, with methodically deactivated motifs, we show that inter-motif spacing and specific motif sequences combine to control binding affinity and compositional heterogeneity of multivalent duplexes. A short linker separating strong and weak motifs results in stable duplexes but forms off-register structures at high LC8 concentrations. Contrastingly, long linkers engender lower cooperativity and heterogeneous complexation at low LC8 concentrations. Accordingly, two-mers, rather than the expected three-mers, dominate negative-stain electron-microscopy images of QT2–4. Comparing variants containing weak-strong and strong-strong motif combinations demonstrates sequence also regulates IDP/LC8 assembly. The observed trends persist for trivalent ASCIZ subdomains: QT2–4, with long and short linkers, forms heterogeneous complexes, whereas QT4–6, with similar mid-length linkers, forms homogeneous complexes. Implications of linker length variations for function are discussed. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) are commonly functionalized using targeting ligands to drive their selective uptake in cells of interest. Typical target cell types are cancer cells, which often overexpress distinct surface receptors that can be exploited for NP therapeutics. However, these targeted receptors are also moderately expressed in healthy cells, leading to unwanted off-tumor toxicities. Multivalent interactions between NP ligands and cell receptors have been investigated to increase the targeting selectivity towards cancer cells due to their non-linear response to receptor density. However, to exploit the multivalent effect, multiple variables have to be considered such as NP valency, ligand affinity, and cell receptor density. Here, we synthesize a panel of aptamer-functionalized silica-supported lipid bilayers (SSLB) to study the effect of valency, aptamer affinity, and epidermal growth factor receptor (EGFR) density on targeting specificity and selectivity. We show that there is an evident interplay among those parameters that can be tuned to increase SSLB selectivity towards high-density EGFR cells and reduce accumulation at non-tumor tissues. Specifically, the combination of high-affinity aptamers and low valency SSLBs leads to increased high-EGFR cell selectivity. These insights provide a better understanding of the multivalent interactions of NPs with cells and bring the nanomedicine field a step closer to the rational design of cancer nanotherapeutics. [Display omitted] [ABSTRACT FROM AUTHOR]

The interactions between bacterial lectins and carbohydrates on the host cell surface can mediate bacterial adhesion, invasion, and immune evasion. Multivalency plays a key role in these binding events. However, additional molecular mechanisms greatly impact multivalent binding recognition. To develop specific and effective bacterial inhibitors, a deeper understanding of the complex underlying mechanisms of bacterial adhesion processes is necessary. By interfering with bacterial adhesion, synthetic multivalent glycoconjugates do not only have the potential to improve or replace antibiotic treatments, but also represent useful tools to study carbohydrate‐pathogen interactions. In this review, we highlight a few recent advances in the synthesis and application of synthetic glycan‐based scaffolds to uncover the nature of glycan‐bacteria interactions and to design efficient bacterial inhibitors. [ABSTRACT FROM AUTHOR]

Glycans are ubiquitously expressed sugars, coating the cell and protein surfaces. They are found on many proteins as either short and branched chains or long chains sticking out from special membrane proteins, known as proteoglycans. This sugar cushion, the glycocalyx, modulates specific interactions and protects the cell. Here it is shown that both the expression of proteoglycans and the glycans expressed on the surface of both the host and virus proteins have a critical role in modulating viral attachment to the cell. A mathematical model using SARS‐Cov‐2 as an archetypical virus to study the glycan role during infection is proposed. It is shown that this occurs via a tug‐of‐war of forces. On one side, the multivalent molecular recognition that viral proteins have toward specific host glycans and receptors. On the other side, the glycan steric repulsion that a virus must overcome to approach such specific receptors. By balancing both interactions, viral tropism can be predicted. In other words, the authors can map out the cells susceptible to virus infection in terms of receptors and proteoglycans compositions. [ABSTRACT FROM AUTHOR]