ACS Chem Biol
December 2024
Fibroblast growth factor 2 (FGF2) is a multipotent growth factor and signaling protein that exhibits broad functions across multiple cell types. These functions are often initiated by binding to growth factor receptors and fine-tuned by glycosaminoglycan (GAG)-modified proteins called proteoglycans. The various outputs of FGF2 signaling and functions arise from a dynamic and cell type-specific set of binding partners.
View Article and Find Full Text PDFThe differentiation of placental cytotrophoblasts (CTBs) into the syncytiotrophoblast (STB) layer results in a significant remodeling of the plasma membrane proteome. Here, we use a peroxidase-catalyzed proximity labeling strategy to map the dynamic plasma membrane proteomes of CTBs and STBs. Coupled with mass-spectrometry-based proteomics, we identify hundreds of plasma membrane proteins and observe relative changes in protein abundance throughout differentiation, including the upregulation of the plasma-membrane-localized nonreceptor tyrosine kinase LYN.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2023
This paper investigates upper-limb kinematic reaching responses during a mechanical perturbation to understand interjoint arm coordination used towards powered prosthesis control development. Common prosthesis arm controllers use electromyography sensors with data-driven models to decode muscle activation signals in controlling prosthesis joint movements. However, these control approaches produce non-natural, discrete movements with no guarantee the controller can react to unexpected disturbances during continuous task motion.
View Article and Find Full Text PDFWe report an operationally facile protocol to prepare photoactivatable probes of the bioactive mammalian disaccharide, Man(β1,4)GlcNAc. Using conformationally restricted mannosyl hemi-acetal donors in a one-pot chlorination, iodination and glycosylation sequence, β-mannosides were generated in excellent diastereoselectivities and yields. Upon accessing the disaccharide, we generated the corresponding photoactivatable probes by appending a diazirine-alkyne equipped linker via a condensation reaction between a diazirine-containing linker and C-1 and C-2 derivatized mannosylamines to furnish the desired C-1 and C-2 modified Man(β1,4)GlcNAc-based probes.
View Article and Find Full Text PDFThe presence of glycan modifications at the cell surface and other locales positions them as key regulators of cell recognition and function. However, due to the complexity of glycosylation, the annotation of which proteins bear glycan modifications, which glycan patterns are present, and which proteins are capable of binding glycans is incomplete. Inspired by activity-based protein profiling to enrich for proteins in cells based on select characteristics, these endeavors have been greatly advanced by the development of appropriate glycan-binding and glycan-based probes.
View Article and Find Full Text PDFThe surface proteome or "surfaceome" is a critical mediator of cellular biology, facilitating cell-to-cell interactions and communication with extracellular biomolecules. Constituents of the surfaceome can serve as biomarkers for changing cell states and as targets for pharmacological intervention. While some pathways of cell surface trafficking are well characterized to allow prediction of surface localization, some non-canonical trafficking mechanisms do not.
View Article and Find Full Text PDFHuman milk oligosaccharides (HMOs) are a family of unconjugated soluble glycans found in human breast milk that exhibit a myriad of biological activity. While recent studies have uncovered numerous biological functions for HMOs (antimicrobial, anti-inflammatory & probiotic properties), the receptors and protein binding partners involved in these processes are not well characterized. This can be attributed largely in part to the low affinity and transient nature of soluble glycan-protein interactions, precluding the use of traditional characterization techniques to survey binding partners in live cells.
View Article and Find Full Text PDFCurr Opin Chem Biol
February 2023
Glycosylation is a ubiquitous post-translational modification read by glycan-binding proteins (GBP) to encode important functions, but a robust understanding of these interactions and their consequences can be challenging to uncover. Glycan-GBP interactions are transient and weak, making them difficult to capture, and glycosylation is dynamic and heterogenous, necessitating study in native cellular environments to identify endogenous ligands. Proximity labeling, an experimental innovation that labels biomolecules close to a protein of interest, has recently emerged as a powerful strategy to overcome these limitations, allowing interactors to be tagged in cells for subsequent enrichment and identification by mass spectrometry-based proteomics.
View Article and Find Full Text PDFGlycoproteins bearing mucin domains serve important biological functions, yet they are understudied due to their dense glycosylation. Malaker et al. describe a new tool that will advance the capture, identification, and prediction of new members of the 'mucinome'.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2022
Open-access databases can facilitate data sharing among researchers and provide normative data for objective clinical assessment development, robotic design, and biomechanical modeling. However, most existing databases focus on gait, balance, and hand gestures without providing elbow and shoulder kinematics that are required in activities of daily living. Furthermore, the few existing upper limb datasets include small sample sizes without consistent data collection protocols, which hinder robotic engineers' ability to design robotic devices that accommodate the general population.
View Article and Find Full Text PDFAm J Physiol Cell Physiol
August 2022
Proteoglycans are now well regarded as key facilitators of cell biology. Although a majority of their interactions and functions are attributed to the decorating glycosaminoglycan chains, there is a growing appreciation for the roles of the proteoglycan core protein and for considering proteoglycans as replete protein-glycan conjugates. This appreciation, seeded by early work in proteoglycan biology, is now being advanced and exalted by modern approaches in chemical glycobiology.
View Article and Find Full Text PDFProteoglycans are heterogeneous macromolecular glycoconjugates that orchestrate many important cellular processes. While much attention has focused on the poly-sulfated glycosaminoglycan chains that decorate proteoglycans, other important elements of their architecture, such as core proteins and membrane localization, have garnered less emphasis. Hence, comprehensive structure-function relationships that consider the replete proteoglycan architecture as glycoconjugates are limited.
View Article and Find Full Text PDFCell surface proteins (CSPs) are vital molecular mediators for cells and their extracellular environment. Thus, understanding which CSPs are displayed on cells, especially in different cell states, remains an important endeavor in cell biology. Here, we describe the integration of cell surface engineering with radical-mediated protein biotinylation to profile CSPs.
View Article and Find Full Text PDFPost-translational modifications (PTMs) immensely expand the diversity of the proteome. Glycosylation, among the most ubiquitous PTMs, is a dynamic and multifarious modification of proteins and lipids that generates an omnipresent foliage on the cell surface. The resulting protein glycoconjugates can serve important functions in biology.
View Article and Find Full Text PDFMyogenic differentiation, the irreversible developmental process where precursor myoblast muscle stem cells become contractile myotubes, is heavily regulated by glycosylation and glycan-protein interactions at the cell surface and the extracellular matrix. The glycan-binding protein galectin-1 has been found to be a potent activator of myogenic differentiation. While it is being explored as a potential therapeutic for muscle repair, a precise understanding of its glycoprotein interactors is lacking.
View Article and Find Full Text PDFInteractions between glycans and glycan-binding proteins (GBPs) consist of weak, noncovalent, and transient binding events, making them difficult to study in live cells void of a static, isolated system. Furthermore, the glycans are often presented as protein glycoconjugates, but there are limited efforts to identify these proteins. Proximity labeling permits covalent tagging of the glycoprotein interactors to query GBP in live cells.
View Article and Find Full Text PDFAt the surface of many cells is a compendium of glycoconjugates that form an interface between the cell and its surroundings; the glycocalyx. The glycocalyx serves several functions that have captivated the interest of many groups. Given its privileged residence, this meshwork of sugar-rich biomolecules is poised to transmit signals across the cellular membrane, facilitating communication with the extracellular matrix and mediating important signalling cascades.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2020
Galectin-3 is a glycan-binding protein (GBP) that binds β-galactoside glycan structures to orchestrate a variety of important biological events, including the activation of hepatic stellate cells and regulation of immune responses. While the requisite glycan epitopes needed to bind galectin-3 have long been elucidated, the cellular glycoproteins that bear these glycan signatures remain unknown. Given the importance of the three-dimensional (3D) arrangement of glycans in dictating GBP interactions, strategies that allow the identification of GBP receptors in live cells, where the native glycan presentation and glycoprotein expression are preserved, have significant advantages over static and artificial systems.
View Article and Find Full Text PDFChem Commun (Camb)
November 2019
The 2019 Faraday Discussion on the Nanolithography of Biointerfaces brought together a diverse set of interdisciplinary scientists involved in the seemingly disparate fields of materials science, nanolithography and glycoscience. The setting and format of this meeting renders the experience unique, and anyone in the audience is instantly engaged in the debate. This Faraday Discussion attracted about sixty delegates, ranging from graduate students and early career researchers to full professors.
View Article and Find Full Text PDFGlycosylation is a ubiquitous post-translational modification that decorates proteins and lipids with glycans. These glycans can play critical roles in regulating biological events, and therefore, the discovery of strategies that target these molecules represent an important advancement toward understanding and controlling glycan-mediated cellular phenotypes. We describe the use of a small molecule, surfen, to temporarily silence the functions mediated by heparan sulfate glycosaminoglycans in mouse embryonic stem cells.
View Article and Find Full Text PDFCell surface glycans, such as heparan sulfate (HS), are increasingly identified as co-regulators of growth factor signaling in early embryonic development; therefore, chemical tailoring of HS activity within the cellular glycocalyx of stem cells offers an opportunity to control their differentiation. The growth factors FGF2 and BMP4 are involved in mediating the exit of murine embryonic stem cells (mESCs) from their pluripotent state and their differentiation toward mesodermal cell types, respectively. Here, we report a method for remodeling the glycocalyx of mutant Ext1 mESCs with defective biosynthesis of HS to drive their mesodermal differentiation in an embryoid body culture.
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