scholarly journals Peripheral α-linked N-acetylglucosamine on the carbohydrate moiety of mucin derived from mammalian gastric gland mucous cells: epitope recognized by a newly characterized monoclonal antibody

1996 ◽  
Vol 318 (2) ◽  
pp. 409-416 ◽  
Author(s):  
Kazuhiko ISHIHARA ◽  
Makoto KURIHARA ◽  
Yukinobu GOSO ◽  
Tsukiko URATA ◽  
Hiroyoshi OTA ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Gastric Gland ◽  
Peripheral Region ◽  
Carbohydrate Moiety ◽  
Dependent Manner ◽  
Mucous Cells ◽  
Concentration Dependent Manner ◽  
Mucosal Layer ◽  
Rat Gastric Mucosa ◽  
Derivatives Of

To obtain a tool to study the structural characterization and the detection of mucin derived from the gastric gland mucous cells, we developed a monoclonal antibody, designated HIK1083, against mucin purified from rat gastric mucosa. In an ELISA, HIK1083 reacted strongly with the mucin purified from a deep layer of the corpus and antrum but only slightly reacted with that obtained from the surface mucosal layer. The reaction of mucin and HIK1083 was inhibited by the oligosaccharides obtained by the alkaline borohydride reduction of antigenic mucin. Two purified oligosaccharide alditols reacting with the monoclonal antibody obtained from the antigenic mucin had one and two peripheral α-linked N-acetylglucosamine residues, respectively, according to the evidence from NMR spectroscopy. Moreover, among the commercially available p-nitrophenyl derivatives of monosaccharides, only p-nitrophenyl-N-acetyl-α-d-glucosaminide inhibited the reaction of this monoclonal antibody and the antigenic mucin in a concentration-dependent manner. These results, as well as the immunohistochemical observations, indicate that α-linked N-acetylglucosamine residues are specifically attached to the peripheral region of the carbohydrate moiety of the mucin synthesized in and secreted from the gastric-gland-type cells, and indicate that the monoclonal antibody HIK1083 recognizes this structure.

scholarly journals Identification of a Human Anti-Alpha-Toxin Monoclonal Antibody Against Staphylococcus aureus Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangjie Liu ◽  
Zhangchun Guan ◽  
Yu Liu ◽  
Jingjing Li ◽  
Chenghua Liu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Monoclonal Antibody ◽  
A549 Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Phage Display Technology ◽  
Alpha Hemolysin ◽  
Protective Strategy ◽  
Display Technology ◽  
Hla Binding

Staphylococcus aureus is a major pathogenic bacterium that causes a variety of clinical infections. The emergence of multi-drug resistant mechanisms requires novel strategies to mitigate S. aureus infection. Alpha-hemolysin (Hla) is a key virulence factor that is believed to play a significant role in the pathogenesis of S. aureus infections. In this study, we screened a naïve human Fab library for identification of monoclonal antibodies targeting Hla by phage display technology. We found that the monoclonal antibody YG1 blocked the Hla-mediated lysis of rabbit red blood cells and inhibited Hla binding to A549 cells in a concentration-dependent manner. YG1 also provided protection against acute peritoneal infection, bacteremia, and pneumonia in murine models. We further characterized its epitope using different Hla variants and found that the amino acids N209 and F210 of Hla were functionally and structurally important for YG1 binding. Overall, these results indicated that targeting Hla with YG1 could serve as a promising protective strategy against S. aureus infection.

scholarly journals Photochemical labeling of human erythrocyte membrane proteins with radioiodinated 4-azidosalicylic acid derivatives of G(M3), G(D3), G(M1), and FucG(M1) gangliosides.

1998 ◽  
Vol 45 (2) ◽  
pp. 509-521
Author(s):  
T Pacuszka ◽  
M Panasiewicz
Keyword(s):  
Specific Radioactivity ◽  
Band 3 ◽  
Uv Spectra ◽  
Dependent Manner ◽  
Protein Activity ◽  
Concentration Dependent Manner ◽  
High Specific Radioactivity ◽  
Sds Page ◽  
Erythrocyte Membrane Proteins ◽  
Derivatives Of

Photoreactive gangliosides of high specific radioactivity may prove useful for studies on glycosphingolipid functions. We prepared 4-azidosalicylic acid (ASA) acylated derivatives of GM3, GD3, GM1, and FucGM1 gangliosides (gangliosides-ASA). Gangliosides-ASA were characterized by their TLC mobility, UV spectra, carbohydrate composition, and digestion with leech endoceramidase. After radioiodination to about 200 Ci/mmole gangliosides-ASA were used for photochemical labeling of human erythrocytes. Radioiodinated gangliosides-ASA were incorporated into erythrocytes in a time and concentration dependent manner, the kinetics and extent of incorporation being similar for all the gangliosides-ASA used. Radioiodinated gangliosides-ASA incorporated into erythrocytes were resistant to trypsin digestion while treatment with 1% BSA removed about 90% of the label. Incubation with cholera toxin protected radioiodinated GM1-ASA and, to a lesser extent, FucGM1-ASA but not GM3-ASA and GD3-ASA, against removal with BSA. After photolysis about 40-50% of radioactivity was firmly bound to erythrocyte lipids and proteins. The ratio of lipid- to protein-bound radioactivity ranged from 2.2:1 to 3.2:1. Photolabeled proteins were analyzed by SDS/PAGE followed by autoradiography. Band 3 was the most extensively photolabeled protein with all the radioiodinated gangliosides-ASA used. DIDS, an inhibitor of band 3 protein activity, caused reduction in photolabeling of this protein by about 20%.

scholarly journals Ligation of the α2-macroglobulin signalling receptor on macrophages induces protein phosphorylation and an increase in cytosolic pH

1995 ◽  
Vol 309 (1) ◽  
pp. 151-158 ◽  
Author(s):  
U K Misra ◽  
G Gawdi ◽  
S V Pizzo
Keyword(s):  
Monoclonal Antibody ◽  
Growth Factors ◽  
Protein Phosphorylation ◽  
Tyrosine Phosphorylation ◽  
Kinase Inhibitor ◽  
Density Lipoprotein ◽  
Ligand Concentration ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cytosolic Ph

We have recently described an alpha 2-macroglobulin (alpha 2M) signalling receptor which is distinct from the low-density lipoprotein-related protein/alpha 2M receptor (LRP/alpha 2MR). Ligation of the macrophage signalling receptor by alpha 2M-methylamine stimulates production of several second messengers and involves a pertussis toxin-insensitive G-protein. We now report that binding of alpha 2M-methylamine, or the cloned M(r) = 20,000 receptor-binding fragment from rat alpha 1M, to macrophage alpha 2M signalling receptors induces protein phosphorylation. By use of a monoclonal antibody to phospholipase C gamma l (PLC gamma l) we were able to identify it as one target for protein phosphorylation. Phosphorylation was time and concentration dependent, being optimal at about 60 s of incubation and a 100-200 nM ligand concentration. By use of a second monoclonal antibody directed against phosphotyrosine, we were able to demonstrate that at least a portion of the label was incorporated into one or more tyrosine residues. PLC gamma l phosphorylation was then studied in membrane preparations at 4 degrees C in order to minimize serine or threonine modification. Preincubation of macrophage membranes with genistein, a tyrosine kinase inhibitor, drastically reduced phosphorylation of PLC gamma l. Receptor-associated protein, which blocks alpha 2M binding to LRP/alpha 2MR but not to the alpha 2M signalling receptor, had no effect on alpha 2M-methylamine-induced tyrosine phosphorylation of PLC gamma l. Binding of lactoferrin to LRP/alpha 2MR failed to induce phosphorylation of PLC gamma l, further supporting the hypothesis that the alpha 2M signalling receptor and LRP/alpha 2MR are distinct entities. Growth factors which induce tyrosine phosphorylation typically cause a rise in cytosolic pH. Binding of a2M-methylamine to macrophages also gradually increased the intracellular pH in a concentration-dependent manner, being optimal at a 200 nM ligand concentration. The increase in pH was amiloride sensitive. We propose that receptor-recognized forms of a2M may function like growth factors with regard to macrophage regulation.

scholarly journals Involvement of P1 Adhesin in Gliding Motility of Mycoplasma pneumoniae as Revealed by the Inhibitory Effects of Antibody under Optimized Gliding Conditions

2005 ◽  
Vol 187 (5) ◽  
pp. 1875-1877 ◽  
Author(s):  
Shintaro Seto ◽  
Tsuyoshi Kenri ◽  
Tetsuo Tomiyama ◽  
Makoto Miyata
Keyword(s):  
Monoclonal Antibody ◽  
Mycoplasma Pneumoniae ◽  
Conformational Changes ◽  
Gliding Motility ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Slight Effect ◽  
Concentration Dependent Manner ◽  
Gliding Mechanism ◽  
Over Time

ABSTRACT To examine the participation of P1 adhesin in gliding of Mycoplasma pneumoniae, we examined the effects of an anti-P1 monoclonal antibody on individual gliding mycoplasmas. The antibody reduced the gliding speed and removed the gliding cells from the glass over time in a concentration-dependent manner but had only a slight effect on nongliding cells, suggesting that the conformational changes of P1 adhesin and its displacement are involved in the gliding mechanism.

Parietal cells express high levels of Na-K-2Cl cotransporter on migrating into the gastric gland neck

1999 ◽  
Vol 276 (5) ◽  
pp. G1273-G1278 ◽  
Author(s):  
Nichole McDaniel ◽  
Christian Lytle
Keyword(s):  
Cell Division ◽  
Gastric Mucosa ◽  
Anion Exchanger ◽  
Immunofluorescence Microscopy ◽  
Gastric Gland ◽  
Parietal Cells ◽  
Mucous Cells ◽  
Proliferating Cells ◽  
Anion Exchanger 2 ◽  
Rat Gastric Mucosa

Na-K-2Cl cotransport and Cl/[Formula: see text] exchange are prominent mechanisms for Cl−uptake in Cl−-secreting epithelial cells. We used immunofluorescence microscopy to delineate the distributions of Na-K-2Cl cotransporter-1 (NKCC1) and anion exchanger-2 (AE2) proteins in rat gastric mucosa (zymogenic zone). Parietal cells (PCs) above the neck of the gastric gland contained abundant AE2 but little or no NKCC1, whereas those in the neck and base contained high NKCC1 but diminished AE2. Lower levels of NKCC1 were detected in surface mucous cells and in cells comprising the blind ends of all glands. Pulse labeling of proliferating cells with bromodeoxyuridine indicated that new PCs originate in the isthmus with scant NKCC1; the subset of PCs that migrate downward expresses NKCC1 abruptly on entering the neck, within 7 days of cell division. Our results suggest that downwardly migrating PCs replace one mechanism for Cl−entry (Cl/[Formula: see text] exchange) with another (Na-K-2Cl cotransport).

scholarly journals A monoclonal antibody against the nuclear pore complex inhibits nucleocytoplasmic transport of protein and RNA in vivo.

1988 ◽  
Vol 107 (4) ◽  
pp. 1289-1297 ◽  
Author(s):  
C Featherstone ◽  
M K Darby ◽  
L Gerace
Keyword(s):  
Monoclonal Antibody ◽  
Ribosomal Rna ◽  
Nuclear Pore Complex ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Small Proteins

A monoclonal antibody that reacts with proteins in the nuclear pore complex of rat liver (Snow, C. M., A. Senior, and L. Gerace. 1987. J. Cell Biol. 104:1143-1156) has been shown to cross react with similar components in Xenopus oocytes, as determined by immunofluorescence microscopy and immunoblotting. We have microinjected the antibody into oocytes to study the possible role of these polypeptides in nucleocytoplasmic transport. The antibody inhibits import of a large nuclear protein, nucleoplasmin, in a time- and concentration-dependent manner. It also inhibits export of 5S ribosomal RNA and mature tRNA, but has no effect on transcription or intranuclear tRNA processing. The antibody does not affect the rate of diffusion into the nucleus of two small proteins, myoglobin and ovalbumin, indicating that antibody binding does not result in occlusion of the channel for diffusion. This suggests that inhibition of protein and RNA transport occurs by binding of the antibody at or near components of the pore that participate in mediated transport.

scholarly journals Exposure of platelet fibrinogen receptors by a monoclonal antibody to CD9 antigen

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 224-229 ◽  
Author(s):  
T Hato ◽  
K Ikeda ◽  
M Yasukawa ◽  
A Watanabe ◽  
Y Kobayashi
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Lymphoblastic Leukemia ◽  
Combined Treatment ◽  
Creatine Phosphate ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Fibrinogen Binding ◽  
Atp Secretion

Abstract We found that a monoclonal antibody to CD9 antigen, PMA2, induces fibrinogen binding to platelets and examined the mechanism for this. That PMA2 recognized the CD9 antigen was confirmed by its immunoblot- reactivity with a 24,000-dalton protein, reactivity with platelets and common acute lymphoblastic leukemia (ALL) cells, and competitive binding with the ALB6 antibody known as the CD9 antibody. At saturation, PMA2 bound to approximately 46,000 sites per platelet. The binding of 125I-fibrinogen to platelets occurred in a PMA2 concentration-dependent manner and was blocked by EDTA or an anti- glycoprotein (GP)IIb-IIIa monoclonal antibody. PMA2-stimulated platelets caused ATP secretion and thromboxane B2 synthesis under non- stirred conditions. The role of secreted ADP and thromboxane in fibrinogen-binding and subsequent platelet aggregation was studied using creatine phosphate/creatine phosphokinase (CP/CPK) and aspirin. CP/CPK or aspirin alone reduced fibrinogen binding to 20% to 30%; however, this binding was sufficient to support full platelet aggregation. Combined treatment with CP/CPK and aspirin abolished fibrinogen binding and aggregation. These results demonstrate that the binding of IgG molecules to the CD9 antigen exposes fibrinogen receptors through both secreted ADP and thromboxane and that either one of both can expose the receptors to an extent sufficient to aggregate platelets.

scholarly journals Exposure of platelet fibrinogen receptors by a monoclonal antibody to CD9 antigen

Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 224-229
Author(s):  
T Hato ◽  
K Ikeda ◽  
M Yasukawa ◽  
A Watanabe ◽  
Y Kobayashi
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Lymphoblastic Leukemia ◽  
Combined Treatment ◽  
Creatine Phosphate ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Fibrinogen Binding ◽  
Atp Secretion

We found that a monoclonal antibody to CD9 antigen, PMA2, induces fibrinogen binding to platelets and examined the mechanism for this. That PMA2 recognized the CD9 antigen was confirmed by its immunoblot- reactivity with a 24,000-dalton protein, reactivity with platelets and common acute lymphoblastic leukemia (ALL) cells, and competitive binding with the ALB6 antibody known as the CD9 antibody. At saturation, PMA2 bound to approximately 46,000 sites per platelet. The binding of 125I-fibrinogen to platelets occurred in a PMA2 concentration-dependent manner and was blocked by EDTA or an anti- glycoprotein (GP)IIb-IIIa monoclonal antibody. PMA2-stimulated platelets caused ATP secretion and thromboxane B2 synthesis under non- stirred conditions. The role of secreted ADP and thromboxane in fibrinogen-binding and subsequent platelet aggregation was studied using creatine phosphate/creatine phosphokinase (CP/CPK) and aspirin. CP/CPK or aspirin alone reduced fibrinogen binding to 20% to 30%; however, this binding was sufficient to support full platelet aggregation. Combined treatment with CP/CPK and aspirin abolished fibrinogen binding and aggregation. These results demonstrate that the binding of IgG molecules to the CD9 antigen exposes fibrinogen receptors through both secreted ADP and thromboxane and that either one of both can expose the receptors to an extent sufficient to aggregate platelets.

2, 4, 5-Trideoxyhexopyranosides Derivatives of 4’- Demethylepipodophyllotoxin: De novo Synthesis and Anticancer Activity

2020 ◽  
Vol 16 ◽  
Author(s):  
Yapeng Lu ◽  
Li Zhu ◽  
Rui Cai ◽  
Yu Li ◽  
Yu Zhao
Keyword(s):  
Cell Cycle ◽  
Cancer Cell ◽  
De Novo ◽  
Building Blocks ◽  
Dependent Manner ◽  
De Novo Synthesis ◽  
Concentration Dependent Manner ◽  
Cycle Arrest ◽  
M Phase ◽  
Derivatives Of

Background: Podophyllotoxin is a natural lignan which possesses anticancer and antiviral activities. Etoposide and teniposide are semisynthetic glycoside derivatives of podophyllotoxin and are increasingly used in cancer medicine. Objective: The present work was aimed to design and synthesize a series of 2, 4, 5-trideoxyhexopyranosides derivatives of 4’-demethylepipodophyllotoxin as novel anticancer agents. Methods: A divergent de novo synthesis of 2, 4, 5-trideoxyhexopyranosides derivatives of 4’-demethylepipodophyllotoxin has been established via palladium-catalyzed glycosylation. The abilities of synthesized glycosides to inhibit the growth of A549, HepG2, SH-SY5Y, KB/VCR and HeLa cancer cells were investigated by MTT assay. Flow cytometric analysis of cell cycle with propidium iodide DNA staining was employed to observe the effect of compound 5b on cancer cell cycle. Results: Twelve D and L monosaccharides derivatives 5a-5l have been efficiently synthesized in three steps from various pyranone building blocks employing de novo glycosylation strategy. D-monosaccharide 5b showed highest cytotoxicity on five cancer cell lines with the IC50 values from 0.9 to 6.7 mM. It caused HepG2 cycle arrest at G2/M phase in a concentration-dependent manner. Conclusion: The present work leads to the development of novel 2, 4, 5-trideoxyhexopyranosides derivatives of 4’- demethylepipodophyllotoxin. The biological results suggested that the replacement of the glucosyl moiety of etoposide with 2, 4, 5-trideoxyhexopyranosyl is favorable to their cytotoxicity. D-monosaccharide 5b caused HepG2 cycle arrest at G2/M phase in a concentration-dependent manner.

scholarly journals Fungicidal Monoclonal Antibody C7 Interferes with Iron Acquisition in Candida albicans

2011 ◽  
Vol 55 (7) ◽  
pp. 3156-3163 ◽  
Author(s):  
Sonia Brena ◽  
Jonathan Cabezas-Olcoz ◽  
María D. Moragues ◽  
Iñigo Fernández de Larrinoa ◽  
Angel Domínguez ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Candida Albicans ◽  
Iron Uptake ◽  
Iron Homeostasis ◽  
Iron Acquisition ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Content Type ◽  
Related Group ◽  
Upregulated Genes

ABSTRACTWe have developed a monoclonal antibody (MAb), C7, that reacts with the Als3p and enolase present in theCandida albicanscell wall and exerts three anti-Candidaactivities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of MAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile ofC. albicansgrown in the presence of a subinhibitory concentration of MAb C7 (12.5 μg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with MAb C7. Of these, 28 were found to be upregulated and 21 were found to be downregulated. The categories of upregulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the downregulated genes (8/21). Results were validated by real-time PCR. Since these effects resembled those found under iron-limited conditions, the activity of MAb C7 onC. albicansmutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking theTPK1gene and, to a lesser extent, theTPK2gene were less sensitive to the candidacidal effect of MAb C7. FeCl3or hemin at concentrations of ≥7.8 μM reversed the candidacidal effect of MAb C7 onC. albicansin a concentration-dependent manner. The results presented in this study provide evidence that the candidacidal effect of MAb C7 is related to the blockage of the reductive iron uptake pathway ofC. albicans.

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