scholarly journals Selective recognition of anionic cell membranes using targeted liposomes coated with zinc(ii)-bis(dipicolylamine) affinity units

2014 ◽  
Vol 12 (30) ◽  
pp. 5645-5655 ◽  
Author(s):  
Serhan Turkyilmaz ◽  
Douglas R. Rice ◽  
Rachael Palumbo ◽  
Bradley D. Smith
Keyword(s):  
Mammalian Cells ◽  
Cell Membranes ◽  
Selective Recognition ◽  
Membrane Surfaces

Liposomes containing phospholipid-PEG conjugates with terminal zinc(ıı)-bis(dipicolylamine) affinity units selectively target anionic membrane surfaces including the exterior of bacterial and dead/dying mammalian cells.

scholarly journals Pathogenesis of shigella diarrhea. VII. Evidence for a cell membrane toxin receptor involving β1 {arrow} 4-linked N-acetyl-D-glucosamine oligomers

1977 ◽  
Vol 146 (2) ◽  
pp. 535-546 ◽  
Author(s):  
GT Keusch ◽  
M Jacewicz
Keyword(s):  
Cell Membrane ◽  
Cholera Toxin ◽  
Liver Cell ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Cell Membranes ◽  
Proteolytic Enzymes ◽  
Cell Monolayer ◽  
Toxin Receptor ◽  
Toxin Uptake

The binding of ShigeUa dysenteriae 1 cytotoxin to HeLa cells in culture and to isolated rat liver cell membranes was studied by means of an indirect consumption assay of toxicity from the medium, or by determination of cytotoxicity to the HeLa cell monolayer. Both liver cell membranes and HeLa cells removed toxicity from the medium during incubation, in contrast to WI-38 and Y-1 mouse adrenal tumor cells, both of which neither bound nor were affected by the toxin. Uptake of toxin was directly related to concentration of membranes added, time,and temperature, and indirectly related to the ionic strength of the buffer used. The chemical nature of the membrane receptor was characterized by using three principal approaches: (a) enzymatic sensitivity; (b) competitive inhibition and (c) receptor blockade studies. The receptor was destroyed by proteolytic enzymes, phospholipases (which markedly altered the gross appearance of the membrane preparation) and by lysozyme, but not by a variety of other enzymes. Of 28 carbohydrate and glycoprotein haptens studied, including cholera toxin and ganglioside, only the chitin oligosaccharide lysozyme substrates, per N-acetylated chitotriose, chitotetraose, and chitopentaose were effective competitive inhibitors. Greatest inhibition was found with the trimer, N, N', N" triacetyl chitotriose. Of three lectins studied as possible receptor blockers, including phytohemagglutinin, concanavalin A, and wheat germ agglutinin, only the latter, which is known to possess specific binding affinity for N, N', N" triacetyl chitotriose, was able to block toxin uptake. Evidence from all three approaches indicate, therefore, existence of a glycoprotein toxin receptor on mammalian cells, with involvement of oligomeric β1{arrow}4-1inked N-acetyl glucosamine in the receptor. This receptor is clearly distinct from the G(M1) ganglioside thought to be involved in the binding of cholera toxin to the cell membrane of a variety of cell types susceptible to its action.

Multifunctional Cationic Poly(p-phenylene vinylene) Polyelectrolytes for Selective Recognition, Imaging, and Killing of Bacteria Over Mammalian Cells

2011 ◽  
Vol 23 (41) ◽  
pp. 4805-4810 ◽  
Author(s):  
Chunlei Zhu ◽  
Qiong Yang ◽  
Libing Liu ◽  
Fengting Lv ◽  
Shayu Li ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Selective Recognition ◽  
Phenylene Vinylene ◽  
Recognition Imaging

DISEASED RED BLOOD CELLS STUDIED BY ATOMIC FORCE MICROSCOPY

2002 ◽  
Vol 01 (05n06) ◽  
pp. 683-688 ◽  
Author(s):  
YONG CHEN ◽  
JIYE CAI ◽  
JINGXIAN ZHAO
Keyword(s):  
Lung Cancer ◽  
Atomic Force Microscopy ◽  
Cell Membrane ◽  
Erythrocyte Membrane ◽  
Mammalian Cells ◽  
Membrane Surface ◽  
Force Microscopy ◽  
Membrane Surfaces ◽  
Atomic Force ◽  
Mean Width

In recent years, many mammalian cells, especially erythrocytes because of simpleness of their membrane surfaces, were widely studied by atomic force microscopy. In our study, diseased erythrocytes were taken from patients of lung cancer, myelodisplastic syndrome (MDS), and so on. We obtained many clear topographical images of numerous erythrocytes, single erythrocyte, and ultramicrostructure of erythrocyte membrane surfaces from normal persons and patients. By studying the red cells of lung cancer patients, we found that many erythrocytes of lung cancer patient have changed into echinocytes. One erythrocyte has 10–20 short projections, most of which, with a mean width of 589.0 nm and a length of 646.7 nm, are on the edge of cell. The projections in the center of echinocytes are lodged and embedded, but in conventional model of echinocytes, the projections in the center stretch outside cell membrane, so a novel model of erythrocytes was designed in our paper. After observation of microstructure of MDS patient's erythrocyte membrane surface, we found that many apertures with different diameters of tens to hundreds nanometers appeared on the surface of cell membrane. It can be concluded that AFM may be widely applied in clinic pathological inspection.

Bioorthogonal chemistry for selective recognition, separation and killing bacteria over mammalian cells

2016 ◽  
Vol 52 (17) ◽  
pp. 3482-3485 ◽  
Author(s):  
Zhenhua Li ◽  
Zhen Liu ◽  
Zhaowei Chen ◽  
Enguo Ju ◽  
Wei Li ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Mammalian Cells ◽  
Selective Recognition ◽  
Bioorthogonal Chemistry ◽  
New Strategy

We report a new strategy for selective recognition, separation and killing bacteria using metabolic engineering and bioorthogonal chemistry.

scholarly journals An Evolutionarily Conserved Helix Mediates Ameloblastin-Cell Interaction

2020 ◽  
Vol 99 (9) ◽  
pp. 1072-1081 ◽  
Author(s):  
J. Su ◽  
R.A. Bapat ◽  
G. Visakan ◽  
J. Moradian-Oldak
Keyword(s):  
Cell Membranes ◽  
Surface Membrane ◽  
Cell Interaction ◽  
Sequence Motifs ◽  
Enamel Matrix Proteins ◽  
Binding Domains ◽  
Membrane Surfaces ◽  
Cell Matrix ◽  
Evolutionarily Conserved ◽  
And Function

Ameloblastin (Ambn) has the potential to regulate cell-matrix adhesion through familiar cell-binding domains, but the proposed sequence motifs are not highly conserved across species. Here, we report that Ambn binds to ameloblast-like cell membranes through a highly evolutionary conserved amphipathic helix-forming (AH) motif encoded by exon 5. We applied high-resolution confocal microscopy to show colocalization of Ambn with ameloblast membrane surfaces in developing mouse incisors. Using a series of Ambn-derived peptides and Ambn variants, we showed that Ambn binds to cell membranes through a motif within the sequence encoded by exon 5. Using peptides derived from the N- or C-termini of this sequence, as well as Ambn variants that lacked or had a disrupted AH motif, we demonstrated that the AH motif located at the N-terminus of the sequence is involved in cell-Ambn adhesion. Sequence analysis revealed that this highly conserved AH motif is absent from other enamel matrix proteins, including amelogenin, enamelin, and amelotin. Collectively, these data suggest that Ambn binds to the cell surface membrane via a helix-forming motif and provide insight into the molecular mechanism and function of Ambn in enamel cell-matrix interaction.

A synthetic channel that efficiently inserts into mammalian cell membranes and destroys cancer cells

2018 ◽  
Vol 209 ◽  
pp. 149-159 ◽  
Author(s):  
Jian-Yu Chen ◽  
Wei-Wei Haoyang ◽  
Min Zhang ◽  
Gang Wu ◽  
Zhan-Ting Li ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Mammalian Cell ◽  
Mammalian Cells ◽  
Cell Membranes ◽  
Amino Groups ◽  
Positively Charged ◽  
Strong Ability

A tubular molecule with terminal positively charged amino groups that displays a strong ability to insert into the membrane of mammalian cells.

scholarly journals A PtdIns(3)P-specific probe cycles on and off host cell membranes during Salmonella invasion of mammalian cells

2001 ◽  
Vol 11 (20) ◽  
pp. 1636-1642 ◽  
Author(s):  
K. Pattni ◽  
M. Jepson ◽  
H. Stenmark ◽  
G. Banting
Keyword(s):  
Host Cell ◽  
Mammalian Cells ◽  
Cell Membranes ◽  
Specific Probe ◽  
Host Cell Membranes

High-resolution, extended views of membrane surfaces revealed by fracture-flip

1989 ◽  
Vol 47 ◽  
pp. 738-739
Author(s):  
Pedro Pinto da Silva
Keyword(s):  
High Resolution ◽  
Colloidal Gold ◽  
Cell Membranes ◽  
Freeze Fracture ◽  
Surface Structures ◽  
New Method ◽  
Deep Etching ◽  
Membrane Surfaces ◽  
Routine Identification ◽  
Freeze Etching

I will describe a new method — fracture-flip — that uses commercially available equipment to produce extended views of cell and membrane surfaces. The resolution of this new method permits the routine identification of surface structures down to 5 nm diameter. Moreover, in contrast to freeze-etching/deep-etching, extended views are easily obtained.Conceptally, fracture-flip derives from label-fracture, another method developed in my laboratory. With label-fracture we showed that, after freeze-fracture, the exoplasmic (E) halves of cell membranes are stabilized by, and remain attached to, their platinum/carbon replicas. This allows the observation of co-incident views of the Pt/C replica of the E face, and of the distribution of colloidal gold labeled receptors or antigens. This is the sequence of steps in fracture-flip:

scholarly journals Mechanistic insights into GLUT1 activation and clustering revealed by super-resolution imaging

2018 ◽  
Vol 115 (27) ◽  
pp. 7033-7038 ◽  
Author(s):  
Qiuyan Yan ◽  
Yanting Lu ◽  
Lulu Zhou ◽  
Junling Chen ◽  
Haijiao Xu ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Cell Membranes ◽  
Molecular Mechanisms ◽  
Glucose Transporter ◽  
Super Resolution ◽  
Average Diameter ◽  
Activation Mechanism ◽  
Membrane Expression ◽  
Close Relationship ◽  
Resolution Imaging

The glucose transporter GLUT1, a plasma membrane protein that mediates glucose homeostasis in mammalian cells, is responsible for constitutive uptake of glucose into many tissues and organs. Many studies have focused on its vital physiological functions and close relationship with diseases. However, the molecular mechanisms of its activation and transport are not clear, and its detailed distribution pattern on cell membranes also remains unknown. To address these, we first investigated the distribution and assembly of GLUT1 at a nanometer resolution by super-resolution imaging. On HeLa cell membranes, the transporter formed clusters with an average diameter of ∼250 nm, the majority of which were regulated by lipid rafts, as well as being restricted in size by both the cytoskeleton and glycosylation. More importantly, we found that the activation of GLUT1 by azide or MβCD did not increase its membrane expression but induced the decrease of the large clusters. The results suggested that sporadic distribution of GLUT1 may facilitate the transport of glucose, implying a potential association between the distribution and activation. Collectively, our work characterized the clustering distribution of GLUT1 and linked its spatial structural organization to the functions, which would provide insights into the activation mechanism of the transporter.

Quantum dots modified with quaternized poly(dimethylaminoethyl methacrylate) for selective recognition and killing of bacteria over mammalian cells

The Analyst ◽  
2016 ◽  
Vol 141 (11) ◽  
pp. 3328-3336 ◽  
Author(s):  
Qin Tu ◽  
Chao Ma ◽  
Chang Tian ◽  
Maosen Yuan ◽  
Xiang Han ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Click Chemistry ◽  
Mammalian Cells ◽  
Selective Recognition ◽  
Dimethylaminoethyl Methacrylate

Quantum dots modified with quaternized poly(dimethylaminoethyl methacrylate) were prepared by simple copper-free click chemistry for the selective recognition and killing of bacterial over mammalian cells.

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