Publications by authors named "Christopher H Taron"

Fosmids and cosmids are vectors frequently used in functional metagenomic studies. With a large insert capacity (around 30 kb) they can encode dozens of cloned genes or in some cases, entire biochemical pathways. Fosmids with cloned inserts can be transferred to heterologous hosts and propagated to enable screening for new enzymes and metabolites.

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  • - The study focuses on zwitterions phosphorylcholine (PC) and phosphoethanolamine (PE), which are commonly attached to sugars in biological structures like polysaccharides and glycoconjugates, playing a role in how certain parasites evade host immunity by modifying N-glycans and glycosphingolipids.
  • - Researchers used functional metagenomic screening to find a novel bacterial enzyme, GlcNAc-PDase, that specifically removes PC from the sugar N-acetylglucosamine (GlcNAc-6-PC), showing strong substrate preference and limited activity on other modified sugars.
  • - GlcNAc-PDase is classified in a new subfamily of the
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We report here the first occurrence of an adenosine deaminase-related growth factor (ADGF) that deaminates adenosine 5' monophosphate (AMP) in preference to adenosine. The ADGFs are a group of secreted deaminases found throughout the animal kingdom that affect the extracellular concentration of adenosine by converting it to inosine. The AMP deaminase studied here was first isolated and biochemically characterized from the roman snail Helix pomatia in 1983.

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Complete -glycosite characterization, including identification of the peptides, localization of the glycosites, and mapping of the glycans, has been a persistent challenge in -glycoproteomics owing to the technical challenges surrounding -glycan analysis. Multi-glycosylated peptides pose an even greater challenge owing to their potential heterogeneity. Ultraviolet photodissociation (UVPD) can localize multiple post-translational modifications and is well-suited for the characterization of glycans.

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N-glycosylation is implicated in cancers and aberrant N-glycosylation is recognized as a hallmark of cancer. Here, we mapped and compared the site-specific N-glycoproteomes of colon cancer HCT116 cells and isogenic non-tumorigenic DNMT1/3b double knockout (DKO1) cells using Fbs1-GYR N-glycopeptide enrichment technology and trapped ion mobility spectrometry. Many significant changes in site-specific N-glycosylation were revealed, providing a molecular basis for further elucidation of the role of N-glycosylation in protein function.

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  • This study investigates the role of serum N-glycans as potential biomarkers for infections in rhesus macaques, specifically during infection with the parasitic worm Brugia malayi, which causes lymphatic filariasis in humans.
  • Researchers utilized advanced techniques (MALDI-TOF-MS and HILIC-UPLC) to analyze changes in N-glycan profiles over time, starting from infection onset, with notable changes observed as soon as 5 weeks post-infection.
  • The findings highlight that specific alterations in N-glycan structures may distinctively correlate with lymphatic filariasis, as compared to changes seen with other infections, like those caused by dog heartworm Dirofilaria immitis.
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  • Millions are infected with filarial nematodes, causing diseases like lymphatic filariasis (LF), and while elimination efforts have decreased infections, better diagnostic tools are needed to monitor populations.
  • Researchers explored the glycan structure of the filarial nematode Brugia malayi, identifying key glycan types through specialized techniques and demonstrating their potential as antigens for diagnostics.
  • The study found that anti-glycan antibodies from hosts, particularly in infected humans and rhesus macaques, responded to B. malayi glycans, indicating these glycan markers could help in diagnosing and monitoring LF.
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Characterization of mucin-type -glycans linked to serine/threonine of glycoproteins is technically challenging, in part, due to a lack of effective enzymatic tools that enable their analysis. Recently, several -glycan-specific endoproteases that can cleave the protein adjacent to the appended glycan have been described. Despite significant progress in understanding the biochemistry of these enzymes, known -glycoproteases have specificity constraints, such as inefficient cleavage of glycoproteins bearing sialylated -glycans, high selectivity for certain types of glycoproteins, or protein sequence bias.

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It has been predicted that 30 to 80% of archaeal genomes remain annotated as hypothetical proteins with no assigned gene function. Further, many archaeal organisms are difficult to grow or are unculturable. To overcome these technical and experimental hurdles, we developed a high-throughput functional genomics screen that utilizes capillary electrophoresis (CE) to identify nucleic acid modifying enzymes based on activity rather than sequence homology.

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Combinations of ribonucleases (RNases) are commonly used to digest RNA into oligoribonucleotide fragments prior to liquid chromatography-mass spectrometry (LC-MS) analysis. The distribution of the RNase target sequences or nucleobase sites within an RNA molecule is critical for achieving a high mapping coverage. Cusativin and MC1 are nucleotide-specific endoribonucleases encoded in the cucumber and bitter melon genomes, respectively.

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Glycosylation is important in biology, contributing to both protein conformation and function. Structurally, glycosylation is complex and diverse. This complexity is reflected in the topology, composition, monosaccharide linkages, and isomerism of each oligosaccharide.

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Background: Sulfate modification of N-glycans is important for several biological functions such as clearance of pituitary hormones or immunoregulation. Yet, the prevalence of this N-glycan modification and its functions remain largely unexplored. Characterization of N-glycans bearing sulfate modifications is hampered in part by a lack of enzymes that enable site-specific detection of N-glycan sulfation.

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  • Protein glycosylation involves attaching carbohydrates to proteins, which influences their structure and function, and abnormal glycosylation can indicate diseases before symptoms arise.
  • There is an increasing demand for reliable high-throughput methods for analyzing glycans at scale, especially since existing methods are limited to smaller analyses.
  • The study assessed the GlycoWorks RapiFluor-MS N-Glycan Kit combined with HILIC-UHPLC on 335 human plasma samples, demonstrating that the method is highly robust and repeatable, suitable for large-scale IgG N-glycan profiling.
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The BLL lectin from the edible Japanese "Kurokawa" mushroom (Boletopsis leucomelaena) was previously reported to bind to N-glycans harboring terminal N-acetylglucosamine (GlcNAc) and to induce apoptosis in a leukemia cell line. However, its gene has not been reported. In this study, we used a transcriptomics-based workflow to identify a full-length transcript of a BLL functional ortholog (termed BGL) from Boletopsis grisea, a close North American relative of B.

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Sialic acids are a family of related sugars that play essential roles in many biological events intimately linked to cellular recognition in both health and disease. Sialidases are therefore orchestrators of cellular biology and important therapeutic targets for viral infection. Here, we sought to define if uncharacterized sialidases would provide distinct paradigms in sialic acid biochemistry.

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Dietary habits have been associated with alterations of the human gut resident microorganisms contributing to obesity, diabetes and cancer. In Western diets, red meat is a frequently eaten food, but long-term consumption has been associated with increased risk of disease. Red meat is enriched in N-glycolylneuraminic acid (Neu5Gc) that cannot be synthesized by humans.

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Further characterization of essential systems in the parasitic filarial nematode Brugia malayi is needed to better understand its biology, its interaction with its hosts, and to identify critical components that can be exploited to develop novel treatments. The production of glycophosphatidylinositol-anchored proteins (GPI-APs) is essential for eukaryotic cellular and physiological function. In addition, GPI-APs perform many important roles for cells.

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The yeast has been a successful host for the production of heterologous proteins for over 30 years. Currently, the galactose-/lactose-inducible and glucose-repressible promoter (P ) is the most widely used promoter to drive recombinant protein expression in However, P is not fully repressed in the presence of glucose and significant protein expression still occurs. Thus, P is not suitable in processes where tight regulation of heterologous gene expression is required.

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Filariases are diseases caused by infection with filarial nematodes and transmitted by insect vectors. The filarial roundworm Dirofilaria immitis causes heartworm disease in dogs and other carnivores. D.

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Exosialidases are glycoside hydrolases that remove a single terminal sialic acid residue from oligosaccharides. They are widely distributed in biology, having been found in prokaryotes, eukaryotes, and certain viruses. Most characterized prokaryotic sialidases are from organisms that are pathogenic or commensal with mammals.

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  • - Glycosylation, a key modification of serum proteins, is linked to various human diseases, but there's limited knowledge about glycosylation in other mammals, particularly dogs.
  • - This study utilizes advanced techniques to analyze the glycosylation patterns in canine serum, revealing notable differences from human serum, like lower levels of certain glycans.
  • - The findings will provide a foundational reference for upcoming research on canine health and disease through serum analysis.
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Summary: Many eukaryotic proteins are modified by N-glycans. Liquid chromatography (ultra-performance -UPLC and high-performance-HPLC) coupled with mass spectrometry (MS) is conventionally used to characterize N-glycan structures. Software can automatically assign glycan structures by matching their observed retention times and masses with standardized values in reference databases.

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Exoglycosidases are often used for detailed characterization of glycan structures. Bovine kidney α-fucosidase is commonly used to determine the presence of core α1-6 fucose on N-glycans, an important modification of glycoproteins. Recently, several studies have reported that removal of core α1-6-linked fucose from N-glycans labeled with the reactive N-hydroxysuccinimide carbamate fluorescent labels 6-aminoquinolyl-N-hydroxysuccinimidylcarbamate (AQC) and RapiFluor-MS is severely impeded.

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Here we report evidence that new aminoquinoline N-glycan fluorescent labels interfere with the release of core α(1-6) fucose from N-glycans by bovine kidney α-l-fucosidase (BKF). BKF is a commonly employed exoglycosidase for core α(1-6) fucose determination. Molecular simulations of the bound and unbound Fuc-α(1-6)-GlcNAc, where GlcNAc is situated at the reducing end for all N-glycans, suggest that the reduced BKF activity may be due to a nonoptimal fit of the highest populated conformers in the BKF active binding site at room temperature.

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