scholarly journals Development of C-type lectin-oriented surfaces for high avidity glycoconjugates: towards mimicking multivalent interactions on the cell surface

2020 ◽  
Vol 18 (25) ◽  
pp. 4763-4772 ◽  
Author(s):  
Vanessa Porkolab ◽  
Carlo Pifferi ◽  
Ieva Sutkeviciute ◽  
Stefania Ordanini ◽  
Marwa Taouai ◽  
...  
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
High Avidity ◽  
Multivalent Interactions ◽  
Multivalent Effect

Here we described C-type lectin-oriented surfaces for SPR analysis. They allow the preservation of receptor topology, accessibility of binding sites, better evaluation of high avidity compounds and assessment of multivalent effect at cell surface.

scholarly journals Cell surface-binding sites for progesterone mediate calcium uptake in human sperm.

1991 ◽  
Vol 266 (28) ◽  
pp. 18655-18659 ◽  
Author(s):  
P.F. Blackmore ◽  
J. Neulen ◽  
F. Lattanzio ◽  
S.J. Beebe
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Calcium Uptake ◽  
Human Sperm ◽  
Surface Binding ◽  
Cell Surface Binding

Target cell surface glycoconjugates and neural induction in an amphibian

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 39-51
Author(s):  
Lydie Gualandris ◽  
Pierre Rouge ◽  
Anne-Marie Duprat
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Neural Induction ◽  
Specific Receptor ◽  
Con A ◽  
Neural Signal ◽  
Electrophysiological Properties ◽  
Ionic Fluxes ◽  
Target Membrane ◽  
Cell Surface Glycoconjugates

The possible involvement of target membrane specific receptor(s) in the transmission of the neural signal leading to activation of the intracellular machinery involved in the process of neural determination, has been examined using lectin probes (Con A, succinylated-ConA, LcA, PsA and SBA). Not only Con A binding sites but many different glycoconjugated molecules (α-Dgalactose, N-acetyl-D-galactosamine, α-D-fucose, N-acetyl-D-glucosamine, etc.) would have to be involved, if neural receptor(s) are invoked to explain initiation of neural induction. We show here that the close involvement of such receptor molecules in neural induction is so far hypothetical and remains to be demonstrated. Moreover we are inclined to the view of Barth and others who suggested that ionic fluxes and physicochemical and electrophysiological properties of the target membrane could play a crucial role in neural induction.

Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum

1986 ◽  
Vol 64 (8) ◽  
pp. 722-732 ◽  
Author(s):  
J. D. Mee ◽  
D. M. Tortolo ◽  
M. B. Coukell
Keyword(s):  
Light Scattering ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Binding Sites ◽  
Large Fraction ◽  
Cell Types ◽  
The Other ◽  
Deficient Mutant ◽  
Camp Phosphodiesterase ◽  
Intracellular Cgmp

During development, prestalk and prespore cells of Dictyostelium discoideum become organized in multicellular structures. This physical association makes it difficult to characterize the two cell types biochemically and physiologically. In the present study, we have separated prestalk and prespore cells from 16-h slugs by the method of Tsang and Bradbury and have examined a number of chemotaxis-associated properties of these cells. When assayed on phosphate-buffered agar under both gradient and nongradient conditions, isolated prestalk cells responded chemotactically to cAMP and, unexpectedly, to folate and certain folate derivatives. In contrast, separated prespore cells failed to respond appreciably to any of these compounds. Neither prestalk nor prespore cells of strain HC91 exhibited a cAMP-induced increase in intracellular cGMP. However, a cGMP response was observed in both prestalk and prespore cells of strain NP368, a cGMP phosphodiesterase deficient mutant. Both cell types exhibited comparable cAMP-mediated light-scattering changes and possessed similar levels of surface cAMP- and folate-binding sites. On the other hand, prestalk cells had at least fourfold higher cAMP phosphodiesterase and folate deaminase activities than prespore cells, and a large fraction of both activities was on the cell surface. Therefore, the greater chemotactic response of prestalk cells to cAMP and folate on agar might be due, in part, to their increased capacity to generate a chemoattractant gradient. Results obtained in this study demonstrate that prestalk and prespore cells separated by this procedure can be used in certain physiological as well as biochemical experiments.

scholarly journals Conformational epitopes at cadherin calcium-binding sites and p120-catenin phosphorylation regulate cell adhesion

2012 ◽  
Vol 23 (11) ◽  
pp. 2092-2108 ◽  
Author(s):  
Yuliya I. Petrova ◽  
MarthaJoy M. Spano ◽  
Barry M. Gumbiner
Keyword(s):  
Cell Surface ◽  
Conformational Changes ◽  
Binding Sites ◽  
Calcium Binding ◽  
Cell Types ◽  
P120 Catenin ◽  
Physiological Regulation ◽  
Conformational Epitopes ◽  
Calcium Binding Sites ◽  
E Cadherin

We investigated changes in cadherin structure at the cell surface that regulate its adhesive activity. Colo 205 cells are nonadhesive cells with a full but inactive complement of E-cadherin–catenin complexes at the cell surface, but they can be triggered to adhere and form monolayers. We were able to distinguish the inactive and active states of E-cadherin at the cell surface by using a special set of monoclonal antibodies (mAbs). Another set of mAbs binds E-cadherin and strongly activates adhesion. In other epithelial cell types these activating mAbs inhibit growth factor–induced down-regulation of adhesion and epithelial morphogenesis, indicating that these phenomena are also controlled by E-cadherin activity at the cell surface. Both types of mAbs recognize conformational epitopes at different interfaces between extracellular cadherin repeat domains (ECs), especially near calcium-binding sites. Activation also induces p120-catenin dephosphorylation, as well as changes in the cadherin cytoplasmic domain. Moreover, phospho-site mutations indicate that dephosphorylation of specific Ser/Thr residues in the N-terminal domain of p120-catenin mediate adhesion activation. Thus physiological regulation of the adhesive state of E-cadherin involves physical and/or conformational changes in the EC interface regions of the ectodomain at the cell surface that are mediated by catenin-associated changes across the membrane.

Participation of concanavalin A binding sites in the interaction between Trypanosoma cruzi and macrophages

1983 ◽  
Vol 62 (1) ◽  
pp. 287-299
Author(s):  
M.N. Meirelles ◽  
A. Martinez-Palomo ◽  
T. Souto-Padron ◽  
W. De Souza
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Trypanosoma Cruzi ◽  
Uniform Distribution ◽  
Concanavalin A ◽  
Binding Sites ◽  
Peritoneal Macrophages ◽  
Untreated Mouse ◽  
Mouse Peritoneal Macrophages

Untreated mouse peritoneal macrophages as well as macrophages treated with concanavalin A (ConA) were incubated in the presence of untreated or ConA-treated epimastigotes and trypomastigotes of Trypanosoma cruzi. Treatment of epimastigotes or trypomastigotes with ConA increased or decreased their uptake by macrophages, respectively. Treatment of their macrophages with ConA reduced by 70% and increased by five times the ingestion of epimastigotes and trypomastigotes, respectively. These results are discussed in relation to previous studies on the mobility of ConA receptors in the membrane of the parasite. Using fluorescein- or ferritin-labelled ConA we observed that ConA binding sites located on the plasma membrane of macrophages are internalized during endocytosis of T. cruzi, and observed in association with the membrane of the endocytic vacuole. Vacuoles without parasites showed a uniform distribution of ConA binding sites, while these sites were distributed in patches in vacuoles containing parasites. These results, in association with others previously reported, suggest the involvement of glycoproteins and/or glycolipids localized on the cell surface of T. cruzi and macrophages during the T. cruzi-macrophage interaction.

Locomotory competence and laminin-specific cell surface binding sites are lost during myoblast differentiation

Development ◽  
1989 ◽  
Vol 105 (4) ◽  
pp. 795-802
Author(s):  
S.L. Goodman ◽  
R. Deutzmann ◽  
V. Nurcombe
Keyword(s):  
Cell Surface ◽  
Binding Sites ◽  
Radioligand Binding ◽  
Specific Interaction ◽  
Myoblast Differentiation ◽  
Specific Cell ◽  
Surface Binding ◽  
Cell Surface Binding ◽  
Locomotory Response ◽  
Specific Cell Surface

The specific interaction of embryonal cells with the extracellular matrix (ECM) is one of the principal forces influencing embryonal development (Hay, 1984; Trinkaus, 1984). We used a muscle satellite cell line (MM14dy) to determine the relationship between locomotory response to laminin and the expression of specific cell surface binding sites for it. Time lapse videomicroscopic analysis was used to study the locomotory response and radioligand binding assays and cell attachment assays were used to follow the expression levels of binding sites for laminin and its subfragments E8 and E1–4. We report here the novel finding that the ability of MM14dy to locomote over laminin diminishes and finally vanishes as the cells differentiate. The simultaneous drop in expression of binding sites for laminin is interpreted as being of potential significance during development and repair.

Chemotactic properties, cellular binding and uptake of peptides and peptide derivatives: studies with Tetrahymena thermophila

1992 ◽  
Vol 103 (2) ◽  
pp. 565-570
Author(s):  
V. Leick
Keyword(s):  
Bovine Serum Albumin ◽  
Cell Surface ◽  
Serum Albumin ◽  
Binding Sites ◽  
Bovine Serum ◽  
Tetrahymena Thermophila ◽  
Chemotactic Peptide ◽  
Dansyl Group ◽  
Peptide Derivatives

Receptor-mediated binding of leukocyte chemotactic peptide, N-formylMet-Leu-Phe (fMLP), occurs in the ciliated protozoon Tetrahymena thermophila. In vivo labelling of the cells with N-formylMet-Leu-[3H]Phe ([3H]fMLP) shows that the cells bind the ligand with high affinity (KD = 4 × 10(−9) M to 1 × 10(−8) M). Moreover, Scatchard transformations of the binding data show that there are about 5 × 10(5) binding sites per cell on the cell surface. Two fluorescent derivatives of leukocyte chemotactic peptide, N-dansylMet-Leu-Phe (dansMLP) and N-formylMet-Leu-Phe-(N-dansyl-)Lys (fMLPdanLys) compete for the N-formylMet-Leu-Phe (fMLP) binding sites on the cell surface. Moreover, both derivatives have retained significant chemoattracting potentials. Fluorescence from dansMLP, but not from fMLPdansLys and dansyl-beta-endorphin, is internalized preferentially into small vesicles. The differences may, however, reflect that the fluorescence from the dansyl group is strongly quenched by a hydrophilic microenvironment when using the two latter peptide derivatives. In contrast, the dansyl group from dansMLP must be assumed to be embedded in a hydrophobic microenvironment in the vesicular membrane or membrane protein. Rhodamine-labelled bovine serum albumin, egg albumin and cytochrome c as well as dansylated bovine serum albumin, which are poor chemoattractants, are preferentially seen to be internalized into large vesicles (food vacuoles).

Sign in / Sign up

Export Citation Format

Share Document