Glycosylation is an attractive approach to enhance biological properties of pharmaceutical proteins; however, the precise installation of glycans for structure-function studies remains challenging. Here, we describe a chemoenzymatic methodology for glyco-tagging of proteins by peptidoligase catalyzed modification of the -terminus of a protein with a synthetic glycopeptide ester having an -acetyl-glucosamine (GlcNAc) moiety to generate an -GlcNAc modified protein. The GlcNAc moiety can be elaborated into complex glycans by -glycosylation using well-defined sugar oxazolines and mutant forms of endo β--acetylglucosaminidases (ENGases).
View Article and Find Full Text PDFProg Nucl Magn Reson Spectrosc
December 2024
Protein A075L is a β-xylosyltransferase that participates in producing the core of the N-glycans found in VP54, the major viral capsid protein of Paramecium bursaria chlorella virus-1 (PBCV-1). In this study, we present an X-ray crystallographic analysis of the apo form of A075L, along with its complexes with the sugar donor and with a trisaccharide acceptor. The protein structure shows a typical GT-B folding, with two Rossmann-like fold domains, in which the acceptor substrate binds to the N-terminal region, and the nucleotide-sugar donor binds to the C-terminal region.
View Article and Find Full Text PDFDC-SIGN (CD209) and L-SIGN (CD209L) are two C-type lectin receptors (CLRs) that facilitate SARS-CoV-2 infections as viral co-receptors. SARS-CoV-2 manipulates both DC-SIGN and L-SIGN for enhanced infection, leading to interest in developing receptor antagonists. Despite their structural similarity (82% sequence identity), they function differently.
View Article and Find Full Text PDFGalectins (Gals), a family of multifunctional glycan-binding proteins, have been traditionally defined as β-galactoside binding lectins. However, certain members of this family have shown selective affinity toward specific glycan structures including human milk oligosaccharides (HMOs) and blood group antigens. In this work, we explored the affinity of human galectins (particularly Gal-1, -3, -4, -7, and -12) toward a panel of oligosaccharides including HMOs and blood group antigens using a complementary approach based on both experimental and computational techniques.
View Article and Find Full Text PDFObjectives: The aim of this study was to assess the completeness and readability of generative pre-trained transformer-4 (GPT-4)-generated discharge instructions at prespecified reading levels for common pediatric emergency room complaints.
Materials And Methods: The outputs for 6 discharge scenarios stratified by reading level (fifth or eighth grade) and language (English, Spanish) were generated fivefold using GPT-4. Specifically, 120 discharge instructions were produced and analyzed (6 scenarios: 60 in English, 60 in Spanish; 60 at a fifth-grade reading level, 60 at an eighth-grade reading level) and compared for completeness and readability (between language, between reading level, and stratified by group and reading level).
The interactions of glycans with proteins modulate many events related to health and disease. In fact, the establishment of these recognition events and their biological consequences are intimately related to the three-dimensional structures of both partners, as well as to their dynamic features and their presentation on the corresponding cell compartments. NMR techniques are unique to disentangle these characteristics and, indeed, diverse NMR-based methodologies have been developed and applied to monitor the binding events of glycans with their associate receptors.
View Article and Find Full Text PDFProteoglycans (PGs), consisting of glycosaminoglycans (GAGs) linked with the core protein through a tetrasaccharide linkage region, play roles in many important biological events. The chemical synthesis of PG glycopeptides is extremely challenging. In this work, the enzymes required for synthesis of chondroitin sulfate (CS) PG (CSPG) have been expressed and the suitable sequence of enzymatic reactions has been established.
View Article and Find Full Text PDFIn infants, hypercalcemia from elevated parathyroid hormone-related protein (PTHrP) is rare, often signaling neoplasm or renal or urinary anomalies. We report an infant who presented with failure to thrive and hypercalcemia at 10 months old, with initial evaluation showing elevated PTHrP of unclear etiology with imaging negative for neoplasm and no structural anomalies of the kidneys or ureters on ultrasound. Within 6 months of presentation, the patient developed nephrotic syndrome and by 2 years had progressed to end-stage kidney disease, necessitating kidney transplantation.
View Article and Find Full Text PDFWe aimed to define a novel indicator for monitoring antimicrobial use specifically in the Emergency Department Observation Unit (EDOU) and to assess the long-term impact of an institutional education-based antimicrobial stewardship program (ASP) on the antimicrobial prescribing pattern and clinical outcomes in this setting. A quasi-experimental interrupted time-series study was performed from 2011 to 2022. An educational ASP was implemented at the EDOU in 2015.
View Article and Find Full Text PDFBackground: Sexualized drug use (SDU) has become a public health concern in recent years. This study aimed to estimate the prevalence of SDU in gay, bisexual, and other men who have sex with men living with HIV (HIV + GBMSM) in Madrid during 2019/2020 and compare it with data from 2016/2017 in order to detect changes in patterns.
Methods: We analyzed the frequency of SDU in a sample of HIV + GBMSM attending HIV clinics, who participated in an anonymous online survey regarding sexual behavior and recreational drug use.
Calpain-1 and calpain-2 are calcium-dependent Cys-proteases ubiquitously expressed in mammalian tissues with a processive, rather than degradative activity. They are crucial for physiological mammary gland homeostasis as well as for breast cancer progression. A growing number of evidences indicate that their pleiotropic functions depend on the cell type, tissue and biological context where they are expressed or dysregulated.
View Article and Find Full Text PDFThe transmission of hepatitis C virus from viremic donors to seronegative recipients of kidney transplantation is well documented. Pre-transplant administration of direct-acting antivirals prevents viremia, but the seroconversion rate is high. We studied the transmission of the virus through the transplanted tissue by determining viral RNA in 15 kidneys from 8 deceased viremic donors, 5 males and 3 females aged 52.
View Article and Find Full Text PDFIntroduction: Despite advances in respiratory distress syndrome (RDS) management over the past decade, non-invasive ventilation (NIV) failure is frequent and associated with adverse outcomes. There are insufficient data on the failure of different NIV strategies currently used in clinical practice in preterm infants.
Methods: This was a prospective, multicenter, observational study of very preterm infants [gestational age (GA) <32 weeks] admitted to the neonatal intensive care unit for RDS that required NIV from the first 30 min after birth.
Population growth leads to an increase in the demand for energy, water, and food as cities grow and urbanize. However, the Earth's limited resources are unable to meet these rising demands. Modern farming practices increase productivity, but waste resources and consume too much energy.
View Article and Find Full Text PDFWe herein report the first total synthesis of the Streptococcus pneumoniae serotype 1 (Sp1) oligosaccharide, a unique zwitterionic capsular polysaccharide carrying labile O-acetyl esters. The target oligosaccharides, featuring rare α-2,4-diamino-2,4,6-trideoxy galactose (AAT) and α-galacturonic acids, were assembled up to the 9-mer level, in a highly stereoselective manner using trisaccharide building blocks. The lability of the O-acetyl esters imposed a careful deprotection scheme to prevent migration and hydrolysis.
View Article and Find Full Text PDFBackground: Preterm birth increases the risk for postpartum depression in both mothers and fathers, calling for strategies to alleviate and prevent depressive symptoms in parents of preterm infants. The aim of this study was to assess the association between early parent-infant closeness and later depressive symptoms among parents of preterm infants. We hypothesized that longer duration of closeness associate with fewer depressive symptoms in both parents.
View Article and Find Full Text PDFBreast
December 2022
Background: Breast cancer is the most common malignancy and the second leading cause of cancer-related mortality in Spanish women. Ribociclib in combination with endocrine therapy (ET) has shown superiority in prolonging survival in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) vs. ET alone.
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