Lectin binding by microvillous membranes and coated-pit regions of human syncytial trophoblast

1980 ◽  
Vol 12 (5) ◽  
pp. 599-607 ◽  
Author(s):  
A. Whyte
Keyword(s):  
Lectin Binding ◽  
Syncytial Trophoblast

Trophoblast Cell Membrane Interactions at Implantation

1970 ◽  
Vol 28 ◽  
pp. 310-311
Author(s):  
A. C. Enders
Keyword(s):  
Epithelial Cells ◽  
Cell Membrane ◽  
Membrane Fusion ◽  
Trophoblast Cell ◽  
Membrane Interactions ◽  
Uterine Epithelial Cells ◽  
Functional Complex ◽  
Cytotrophoblast Cells ◽  
Complex Relationships ◽  
Syncytial Trophoblast

The alteration in membrane relationships seen at implantation include 1) interaction between cytotrophoblast cells to form syncytial trophoblast and addition to the syncytium by subsequent fusion of cytotrophoblast cells, 2) formation of a wide variety of functional complex relationships by trophoblast with uterine epithelial cells in the process of invasion of the endometrium, and 3) in the case of the rabbit, fusion of some uterine epithelial cells with the trophoblast.Formation of syncytium is apparently a membrane fusion phenomenon in which rapid confluence of cytoplasm often results in isolation of residual membrane within masses of syncytial trophoblast. Often the last areas of membrane to disappear are those including a desmosome where the cell membranes are apparently held apart from fusion.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

Lectin Binding Studies on RNA Tumor Virus-Infected Cells

1975 ◽  
Vol 33 ◽  
pp. 326-327
Author(s):  
D. C. Hixson
Keyword(s):  
Binding Sites ◽  
Lectin Binding ◽  
Culture Conditions ◽  
3T3 Cells ◽  
Binding Studies ◽  
Con A ◽  
Microscopic Studies ◽  
Tumor Virus ◽  
Infected Cells ◽  
Cell Culture Conditions

The abilities of plant lectins to preferentially agglutinate malignant cells and to bind to specific monosaccharide or oligosaccharide sequences of glycoproteins and glycolipids make them a new and important biochemical probe for investigating alterations in plasma membrane structure which may result from malignant transformation. Electron and light microscopic studies have demonstrated clustered binding sites on surfaces of SV40-infected or tryp- sinized 3T3 cells when labeled with concanavalin A (con A). No clustering of con A binding sites was observed in normal 3T3 cells. It has been proposed that topological rearrangement of lectin binding sites into clusters enables con A to agglutinate SV40-infected or trypsinized 3T3 cells (1). However, observations by other investigators have not been consistent with this proposal (2) perhaps due to differences in reagents used, cell culture conditions, or labeling techniques. The present work was undertaken to study the lectin binding properties of normal and RNA tumor virus-infected cells and their associated viruses using lectins and ferritin-conjugated lectins of five different specificities.

Lectin-Induced RBC Agglutination: Chemical vs. Cryofixation

1980 ◽  
Vol 38 ◽  
pp. 664-665
Author(s):  
Dean A. Handley ◽  
Lanping A. Sung ◽  
Shu Chien
Keyword(s):  
Lectin Binding ◽  
Freeze Substitution ◽  
Electrostatic Charge ◽  
Geometric Parameters ◽  
Comparative Approach ◽  
Chemical Fixation ◽  
Cell Surfaces ◽  
Minimal Cell ◽  
Membrane Stiffness ◽  
Cell Contour

RBC agglutination by lectins represents an interactive balance between the attractive (bridging) force due to lectin binding on cell surfaces and disaggregating forces, such as membrane stiffness and electrostatic charge repulsion (1). During agglutination, critical geometric parameters of cell contour and intercellular distance reflect the magnitude of these interactive forces and the size of the bridging macromolecule (2). Valid ultrastructural measurements of these geometric parameters from agglutinated RBC's require preservation with minimal cell distortion. As chemical fixation may adversely influence RBC geometric properties (3), we used chemical fixation and cryofixation (rapid freezing followed by freeze-substitution) as a comparative approach to examine these parameters from RBC agglutinated with Ulex I lectin.

Specificity of Lectins Labeled with Colloidal Gold to the Exopolymeric Matrix Carbohydrates of the Sulfate-Reducing Bacteria Biofilm Formed on Steel

2020 ◽  
Vol 82 (5) ◽  
pp. 11-20
Author(s):  
D.R. Abdulina ◽  
◽  
L.M. Purish ◽  
G.O. Iutynska ◽  
◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Colloidal Gold ◽  
Steel Surface ◽  
Lectin Binding ◽  
Sulfate Reducing Bacteria ◽  
Gold Particles ◽  
Sulfate Reducing ◽  
Transmission Electron ◽  
Reducing Bacteria

The studies of the carbohydrate composition of the sulfate-reducing bacteria (SRB) biofilms formed on the steel surface, which are a factor of microbial corrosion, are significant. Since exopolymers synthesized by bacteria could activate corrosive processes. The aim of the study was to investigate the specificity of commercial lectins, labeled with colloidal gold to carbohydrates in the biofilm exopolymeric matrix produced by the corrosive-relevant SRB strains from man-caused ecotopes. Methods. Microbiological methods (obtaining of the SRB biofilms during cultivation in liquid Postgate B media under microaerophilic conditions), biochemical methods (lectin-binding analysis of 10 commercial lectins, labeled with colloidal gold), transmission electron microscopy using JEM-1400 JEOL. Results. It was shown using transmission electron microscopy that the binding of lectins with carbohydrates in the biofilm of the studied SRB strains occurred directly in the exopolymerіс matrix, as well as on the surfaces of bacterial cells, as seen by the presence of colloidal gold particles. For detection of the neutral carbohydrates (D-glucose and D-mannose) in the biofilm of almost all studied bacterial strains PSA lectin was the most specific. This lectin binding in biofilms of Desulfotomaculum sp. К1/3 and Desulfovibrio sp. 10 strains was higher in 90.8% and 94.4%, respectively, then for ConA lectin. The presence of fucose in the SRB biofilms was detected using LABA lectin, that showed specificity to the biofilm EPS of all the studied strains. LBA lectin was the most specific to N-аcetyl-D-galactosamine for determination of amino sugars in the biofilm. The amount of this lectin binding in D. vulgaris DSM644 biofilm was 30.3, 10.1 and 9.3 times higher than SBA, SNA and PNA lectins, respectively. STA, LVA and WGA lectins were used to detect the N-acetyl-Dglucosamine and sialic acid in the biofilm. WGA lectin showed specificity to N-acetyl-D-glucosamine in the biofilm of all the studied SRB; maximum number of bounded colloidal gold particles (175 particles/μm2) was found in the Desulfotomaculum sp. TC3 biofilm. STA lectin was interacted most actively with N-acetyl-D-glucosamine in Desulfotomaculum sp. TC3 and Desulfomicrobium sp. TC4 biofilms. The number of bounded colloidal gold particles was in 9.2 and 7.4 times higher, respectively, than using LVA lectin. The lowest binding of colloidal gold particles was observed for LVA lectin. Conclusions. It was identified the individual specificity of the 10 commercial lectins to the carbohydrates of biofilm matrix on the steel surface, produced by SRB. It was estimated that lectins with identical carbohydrates specificity had variation in binding to the biofilm carbohydrates of different SRB strains. Establishing of the lectin range selected for each culture lead to the reduction of the scope of studies and labor time in the researching of the peculiarities of exopolymeric matrix composition of biofilms formed by corrosiverelevant SRB.

scholarly journals Production of nonulosonic acids in the extracellular polymeric substances of “Candidatus Accumulibacter phosphatis”

2021 ◽  
Author(s):  
Sergio Tomás-Martínez ◽  
Hugo B.C. Kleikamp ◽  
Thomas R. Neu ◽  
Martin Pabst ◽  
David G. Weissbrodt ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Lectin Binding ◽  
Wide Distribution ◽  
Sialic Acids ◽  
Animal Cells ◽  
Microbial Life ◽  
Proteomic Data ◽  
Accumulibacter Phosphatis

Abstract Nonulosonic acids (NulOs) are a family of acidic carbohydrates with a nine-carbon backbone, which include different related structures, such as sialic acids. They have mainly been studied for their relevance in animal cells and pathogenic bacteria. Recently, sialic acids have been discovered as an important compound in the extracellular matrix of virtually all microbial life and in “Candidatus Accumulibacter phosphatis”, a well-studied polyphosphate-accumulating organism, in particular. Here, bioaggregates highly enriched with these bacteria (approx. 95% based on proteomic data) were used to study the production of NulOs in an enrichment of this microorganism. Fluorescence lectin-binding analysis, enzymatic quantification, and mass spectrometry were used to analyze the different NulOs present, showing a wide distribution and variety of these carbohydrates, such as sialic acids and bacterial NulOs, in the bioaggregates. Phylogenetic analysis confirmed the potential of “Ca. Accumulibacter” to produce different types of NulOs. Proteomic analysis showed the ability of “Ca. Accumulibacter” to reutilize and reincorporate these carbohydrates. This investigation points out the importance of diverse NulOs in non-pathogenic bacteria, which are normally overlooked. Sialic acids and other NulOs should be further investigated for their role in the ecology of “Ca. Accumulibacter” in particular, and biofilms in general. Key Points •“Ca. Accumulibacter” has the potential to produce a range of nonulosonic acids. •Mass spectrometry and lectin binding can reveal the presence and location of nonulosonic acids. •The role of nonulosonic acid in non-pathogenic bacteria needs to be studied in detail.

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