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Journal of Separation Science Jun 2022We developed a simple high-performance liquid chromatography assay to monitor high-mannose glycans in monoclonal antibodies by monitoring terminal alpha-mannose as a...
We developed a simple high-performance liquid chromatography assay to monitor high-mannose glycans in monoclonal antibodies by monitoring terminal alpha-mannose as a surrogate marker. Analysis of glycan data of therapeutic monoclonal antibodies by 2-aminobenzamide assay showed a linear relationship between high mannose and terminal mannose of Fc glycans. Concanavalin A has a strong affinity to alpha-mannose in glycans of typical therapeutic monoclonal antibodies. To show that terminal mannose binds specifically to Concanavalin A column, exoglycosidase-treated monoclonal antibodies were serially blended with untreated monoclonal antibodies. Linear responses of terminal-mannose binding to the column and comparable data trending with high mannose levels by 2-aminobenzamide assay confirmed that terminal-mannose levels measured by the Concanavalin A column can be used as a surrogate for the prediction of high-mannose levels in monoclonal antibodies. The assay offers a simple, fast, and specific capability for the prediction of high-mannose content in samples compared with traditional glycan profiling by 2-aminobenzamide or mass spectrometry-based methods. When the Concanavalin A column was coupled with protein A column for purification of antibodies from cell culture samples in a fully automated two-dimensional analysis, high-mannose data could be relayed to the manufacturing team in less than 30 min, allowing near-real-time monitoring of high-mannose levels in the cell culture process.
Topics: Antibodies, Monoclonal; Cell Culture Techniques; Chromatography, Affinity; Concanavalin A; Lectins; Mannose; Polysaccharides
PubMed: 35043561
DOI: 10.1002/jssc.202100903 -
Chemistry (Weinheim An Der Bergstrasse,... Sep 2020Synthetic carbohydrate receptors (SCRs) that selectively recognize cell-surface glycans could be used for detection, drug delivery, or as therapeutics. Here we report...
Synthetic carbohydrate receptors (SCRs) that selectively recognize cell-surface glycans could be used for detection, drug delivery, or as therapeutics. Here we report the synthesis of seven new C symmetric tetrapodal SCRs. The structures of these SCRs possess a conserved biaryl core, and they vary in the four heterocyclic binding groups that are linked to the biaryl core via secondary amines. Supramolecular association between these SCRs and five biologically relevant C -O-octyloxy glycans, α/β-glucoside (α/β-Glc), α/β-mannoside (α/β-Man), and β-galactoside (β-Gal), was studied by mass spectrometry, H NMR titrations, and molecular modeling. These studies revealed that selectivity can be achieved in these tetrapodal SCRs by varying the heterocyclic binding group. We found that SCR017 (3-pyrrole), SCR021 (3-pyridine), and SCR022 (2-phenol) bind only to β-Glc. SCR019 (3-indole) binds only to β-Man. SCR020 (2-pyridine) binds β-Man and α-Man with a preference to the latter. SCR018 (2-indole) binds α-Man and β-Gal with a preference to the former. The glycan guests bound within their SCR hosts in one of three supramolecular geometries: center-parallel, center-perpendicular, and off-center. Many host-guest combinations formed higher stoichiometry complexes, 2:1 glycan⋅SCR or 1:2 glycan⋅SCR, where the former are driven by positive allosteric cooperativity induced by glycan-glycan contacts.
Topics: Carbohydrates; Lectins, C-Type; Magnetic Resonance Spectroscopy; Mannose; Mannose Receptor; Mannose-Binding Lectins; Models, Molecular; Molecular Structure; Polysaccharides; Receptors, Artificial; Receptors, Cell Surface
PubMed: 32253776
DOI: 10.1002/chem.202000481 -
Neurochemical Research Aug 2017Glucose is the main peripheral substrate for energy production in the brain. However, as other hexoses are present in blood and cerebrospinal fluid, we have investigated...
Glucose is the main peripheral substrate for energy production in the brain. However, as other hexoses are present in blood and cerebrospinal fluid, we have investigated whether neurons have the potential to metabolize, in addition to glucose, also the hexoses mannose, fructose or galactose. Incubation of primary cerebellar granule neurons in the absence of glucose caused severe cell toxicity within 24 h, which could not be prevented by application of galactose or fructose, while the cells remained viable during incubation in the presence of either mannose or glucose. In addition, cultured neurons produced substantial and almost identical amounts of lactate after exposure to either glucose or mannose, while lactate production was low in the presence of fructose and hardly detectable during incubations without hexoses or with galactose as carbon source. Determination of the K values of hexokinase in lysates of cultured neurons for the hexoses revealed values in the micromolar range for mannose (32 ± 2 µM) and glucose (59 ± 10 µM) and in the millimolar range for fructose (4.4 ± 2.3 mM), demonstrating that mannose is efficiently phosphorylated by neuronal hexokinase. Finally, cultured neurons contained reasonable specific activity of the enzyme phosphomannose isomerase, which is required for isomerization of the hexokinase product mannose-6-phosphate into the glycolysis intermediate fructose-6-phosphate. These data demonstrate that cultured cerebellar granule neurons have the potential and express the required enzymes to efficiently metabolize mannose, while galactose and fructose serve at best poorly as extracellular carbon sources for neurons.
Topics: Animals; Animals, Newborn; Cell Survival; Cells, Cultured; Cerebellum; Mannose; Neurons; Rats; Rats, Wistar
PubMed: 28345119
DOI: 10.1007/s11064-017-2241-9 -
Journal of Clinical Microbiology Nov 1981Using gas-liquid chromatography, we measured five mannose in the serum of six nondiabetic patients with autopsy-proven invasive candidiasis. In all patients serum...
Using gas-liquid chromatography, we measured five mannose in the serum of six nondiabetic patients with autopsy-proven invasive candidiasis. In all patients serum mannose concentrations were higher than mannose levels found in serum from normal adults and children or from patients with catheter-associated candidemia, mucosal candidiasis, and other mycoses. Spinal fluid from two patients with Candida meningitis showed increased free mannose as compared to seven non-inflammatory spinal fluid samples. However, free mannose in the serum of poorly controlled diabetics (blood glucose of greater than or equal to 300 mg/dl) did overlap concentrations in patients with invasive candidiasis. In vitro culture of Candida albicans demonstrated increasing concentrations of mannose associated with growth of the organism. We conclude that physical and chemical assay for mannose in body fluids may be a useful technique to assist in the diagnosis in invasive candidiasis.
Topics: Adolescent; Adult; Candida albicans; Candidiasis; Child; Child, Preschool; Diabetes Mellitus; Female; Humans; Infant; Male; Mannose
PubMed: 7031087
DOI: 10.1128/jcm.14.5.557-562.1981 -
Carbohydrate Research Jul 2019A series of 3-carbamoyl- and 2,3-dicarbamoyl-mannose derivatives were synthesized, conjugated to a fluorescent dye (Cy5, AF 647 or NBD) and their cellular uptake in A549...
A series of 3-carbamoyl- and 2,3-dicarbamoyl-mannose derivatives were synthesized, conjugated to a fluorescent dye (Cy5, AF 647 or NBD) and their cellular uptake in A549 and THP-1 cell lines was studied by FACS. In contrast to earlier studies on carbamoyl mannosides, the observed uptake was not related to carbamoyl group on the mannose residue but rather to the cyanine dye attached, a trend previously observed for Cy5-fructose conjugates. The NBD-conjugates however, showed a temperature and concentration dependent uptake in case of mannose conjugates. These results suggest a profound impact of the dye which should be taken into consideration when studying the uptake of small molecules by dye conjugation.
Topics: A549 Cells; Biological Transport; Chemistry Techniques, Synthetic; Flow Cytometry; Humans; Mannose; Temperature
PubMed: 31252337
DOI: 10.1016/j.carres.2019.06.008 -
Plant Cell Reports Sep 2006The selectable marker system, which utilizes the pmi gene encoding for phosphomannose-isomerase that converts mannose-6-phosphate to fructose-6-phosphate, was adapted...
The selectable marker system, which utilizes the pmi gene encoding for phosphomannose-isomerase that converts mannose-6-phosphate to fructose-6-phosphate, was adapted for Agrobacterium-mediated transformation of cucumber (Cucumis sativus L.). Only transformed cells were capable of utilizing mannose as a carbon source. The highest transformation frequency of 23% was obtained with 10 g/l mannose and 10 g/l sucrose in the medium. Molecular, genetic analysis, and PMI activity assay showed that the regenerated shoots contained the pmi gene and the gene was transmitted to the progeny in a Mendelian fashion. The results indicated that the mannose selection system, which is devoid of the disadvantages of antibiotic or herbicide selection, could be used for cucumber Agrobacterium-mediated transformation.
Topics: Cucumis sativus; Genetic Vectors; Germination; Mannose; Plant Tumors; Plants, Genetically Modified; Seeds; Transformation, Genetic
PubMed: 16565859
DOI: 10.1007/s00299-006-0156-z -
Langmuir : the ACS Journal of Surfaces... Sep 2017Several viral and fungal pathogens, including HIV, SARS, Dengue, Ebola, and Cryptococcus neoformans, display a preponderance of mannose residues on their surface,...
Several viral and fungal pathogens, including HIV, SARS, Dengue, Ebola, and Cryptococcus neoformans, display a preponderance of mannose residues on their surface, particularly during the infection cycle or in harsh environments. The innate immune system, on the other hand, abounds in mannose receptors which recognize mannose residues on pathogens and trigger their phagocytosis. We pose the question if there is an advantage for pathogens to display mannose on their surface, despite these residues being recognized by the immune system. The surface properties and interactions of opposing monolayers of mannobiose (disaccharide of mannose) were probed using atomic force spectroscopy. Unlike its diastereoisomer lactose, mannobiose molecules exhibited lateral packing interactions that manifest on the surface scale as a self-recognizing latch. A break-in force is required for opposing surfaces to penetrate and a breakout (or self-adhesion force) of similar magnitude is required for penetrated surfaces to separate. A hierarchy of self-adhesion forces was distinguished as occurring at the single residue (∼25 pN), cluster (∼250 pN), monolayer (∼1.1 nN), and supramonolayer level. The break-in force and break-out force appear resilient to the presence of simple chaotropes that attenuate a layer of structured water around the mannose surface. The layer of structured water otherwise extends to distances several times longer than a mannobiose residue, indicating a long-range propagation of the hydrogen bonding imposed by the residues. The span of the structured water increases with the velocity of an approaching surface, similar to shear thickening, but fissures at higher approach velocities. Our studies suggest that mannose residues could guide interpathogen interactions, such as in biofilms, and serve as a moated fortress for pathogens to hide behind to resist detection and harsh environments.
Topics: Mannose; Microscopy, Atomic Force; Surface Properties; Virulence; Water
PubMed: 28817934
DOI: 10.1021/acs.langmuir.7b01006 -
Chemical Communications (Cambridge,... Mar 2009Functionalisation of MSN with mannose for PDT applications dramatically improved the efficiency of PDT on breast cancer cells.
Functionalisation of MSN with mannose for PDT applications dramatically improved the efficiency of PDT on breast cancer cells.
Topics: Apoptosis; Cell Line, Tumor; Drug Delivery Systems; HeLa Cells; Humans; Lectins, C-Type; Mannose; Mannose Receptor; Mannose-Binding Lectins; Molecular Structure; Nanoparticles; Photochemotherapy; Receptors, Cell Surface; Silicon Dioxide
PubMed: 19277361
DOI: 10.1039/b900427k -
Medical Oncology (Northwood, London,... Apr 2022Photodynamic therapy (PDT) damages cancer cells via photosensitization using harmless laser irradiation. We synthesized a new photosensitizer, mannose-conjugated-chlorin...
Photodynamic therapy (PDT) damages cancer cells via photosensitization using harmless laser irradiation. We synthesized a new photosensitizer, mannose-conjugated-chlorin e6 (M-chlorin e6), which targets mannose receptors that are highly expressed on M2-like tumor-associated macrophages (M2-TAMs) and cancer cells. In our previous study, we demonstrated that M-chlorin e6 PDT reduces tumor volume and decreases the proportion of M2-TAMs. Whether M-chlorin e6 PDT-treated cancer cells activate tumor immunity remains unclear, although the decrease in M2-TAMs is thought to be a direct injurious effect of M-chlorin e6 PDT. Calreticulin (CRT) is exposed at the surface of the membrane of cancer cells in response to treatment with chemotherapeutic agents such as anthracycline and oxaliplatin. Surface-exposed CRT induces phagocytosis of CRT receptor-positive cells, including macrophages, inducing anticancer immune responses. In the present study, we found that M-chlorin e6 PDT increases CRT on the surface of cancer cells, leading to macrophage phagocytosis of cancer cells. Furthermore, M-chlorin e6 PDT increases CD80CD86 macrophages. These results suggest that M-chlorin e6 PDT exerts anti-tumor effects by both enhancing the phagocytosis of cancer cells and strengthening the anti-tumor phenotype of macrophages.
Topics: Calreticulin; Chlorophyllides; Humans; Macrophages; Mannose; Neoplasms; Phagocytosis; Photochemotherapy
PubMed: 35478050
DOI: 10.1007/s12032-022-01674-3 -
Langmuir : the ACS Journal of Surfaces... Jan 2018Polyethylenimine (PEI) has antimicrobial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli), bacteria but is...
Polyethylenimine (PEI) has antimicrobial activity against Gram-positive (Staphylococcus aureus, S. aureus) and Gram-negative (Escherichia coli, E. coli), bacteria but is highly cytotoxic, and the selective antimicrobial activity against S. aureus is obviously better than that against E. coli. To reduce the cytotoxicity and improve the antibacterial activity against E. coli, we modified PEI with d-mannose through nucleophilic addition between primary amine and aldehyde groups to get mannose-modified polyethylenimine copolymer particles (Man-PEI CPs). The use of mannose may provide good targeting ability toward E. coli pili. The antibacterial activity of Man-PEI CPs was investigated. Man-PEI CPs shows specific and very strong killing capability against E. coli at a concentration of 10 μg/mL, which is the highest antimicrobial efficiency compared to that of unmodified PEI (220 μg/mL). The antibacterial mechanism demonstrated that the enhancement in antibacterial activity is due to specific recognition of the mannose and destroying the cell wall of the bacteria by PEIs. Importantly, the Man-PEI CPs show less cytotoxicity and excellent biocompatibility. The results indicate that Man-PEI CPs have great potential as novel antimicrobial materials to prevent bacterial infections and provide specific applications for killing E. coli.
Topics: Anti-Bacterial Agents; Escherichia coli; HeLa Cells; Humans; Mannose; Materials Testing; Models, Molecular; Molecular Conformation; Polyethyleneimine; Staphylococcus aureus
PubMed: 29304546
DOI: 10.1021/acs.langmuir.7b03556