Differential binding of conA and WGA on the cell surface, the role of sialic acid in their expression and the increased activity of sialidase after cis-Platin treatment

1985 ◽  
Vol 41 (1) ◽  
pp. 93-95 ◽  
Author(s):  
A. Sodhi ◽  
S. B. Prasad
Author(s):  
Tainá Cavalcante ◽  
Mariana Medina Medeiros ◽  
Simon Ngao Mule ◽  
Giuseppe Palmisano ◽  
Beatriz Simonsen Stolf

Carbohydrates or glycans are ubiquitous components of the cell surface which play crucial biological and structural roles. Sialic acids (Sias) are nine-carbon atoms sugars usually present as terminal residues of glycoproteins and glycolipids on the cell surface or secreted. They have important roles in cellular communication and also in infection and survival of pathogens. More than 20 pathogens can synthesize or capture Sias from their hosts and incorporate them into their own glycoconjugates and derivatives. Sialylation of pathogens’ glycoconjugates may be crucial for survival inside the host for numerous reasons. The role of Sias in protozoa such as Trypanosoma and Leishmania was demonstrated in previous studies. This review highlights the importance of Sias in several pathogenic infections, focusing on Leishmania. We describe in detail the contributions of Sias, Siglecs (sialic acid binding Ig-like lectins) and Neuraminidase 1 (NEU 1) in the course of Leishmania infection. A detailed view on the structural and functional diversity of Leishmania-related Sias and host-cell receptors will be provided, as well as the results of functional studies performed with different Leishmania species.


1979 ◽  
Vol 27 (8) ◽  
pp. 1174-1176 ◽  
Author(s):  
P P De Bruyn

Changes in the anionic charge distribution at the luminal face of the endothelium of the sinusoids of the bone marrow have been studied at sites of endocytosis by large bristle coated vesicles and at the sites of molecular permeability through diaphragmed fenestrae. The anionic charge distribution has also been studied at the abluminal aspect of these vessels at sites of transmural blood cell passage. Cationic surface markers such as colloidal iron, native ferritin and polycationic ferritin used at low pH, 1.8, and the use of neuraminidase show that the nonmodified endothelial cell surface has exposed sialic acid groups, which are absent at the sites of these functional specializations. Polycationic ferritin binding over a range of pH levels indicates the prsence of another species of anionic materials present at both the nonmodified cell surface and at the sites of the cell surface modifications. This second group of anionic compounds is neuraminidase resistant and has a pKa higher than that of sialic acid (pKa:2.6).


1975 ◽  
Vol 31 (9) ◽  
pp. 1075-1077 ◽  
Author(s):  
P. K. Ray ◽  
S. Chatterjee

2001 ◽  
Vol 281 (3) ◽  
pp. F391-F399 ◽  
Author(s):  
Daniela Rotin ◽  
Voula Kanelis ◽  
Laurent Schild

The epithelial Na+ channel (ENaC) plays a key role in the regulation of Na+ and water absorption in several epithelia, including those of the distal nephron, distal colon, and lung. Accordingly, mutations in ENaC leading to reduced or increased channel activity cause human diseases such as pseudohypoaldosteronism type I or Liddle's syndrome, respectively. The gain of ENaC function in Liddle's syndrome is associated with increased activity and stability of the channel at the plasma membrane. Thus understanding the regulation of channel processing and trafficking to and stability at the cell surface is of fundamental importance. This review describes some of the recent advances in our understanding of ENaC trafficking, including the role of glycosylation, ENaC solubility in nonionic detergent, targeting signal(s) and hormones. It also describes the regulation of ENaC stability at the cell surface and the roles of the ubiquitin ligase Nedd4 (and ubiquitination) and clathrin-mediated endocytosis in that regulation.


1991 ◽  
Vol 30 (06) ◽  
pp. 290-293 ◽  
Author(s):  
P. Maleki ◽  
A. Martinezi ◽  
M. C. Crone-Escanye ◽  
J. Robert ◽  
L. J. Anghileri

The study of the interaction between complexed iron and tumor cells in the presence of 67Ga-citrate indicates that a phenomenon of iron-binding related to the thermodynamic constant of stability of the iron complex, and a hydrolysis (or anion penetration) of the interaction product determine the uptake of 67Ga. The effects of various parameters such as ionic composition of the medium, nature of the iron complex, time of incubation and number of cells are discussed.


2021 ◽  
Vol 22 (14) ◽  
pp. 7494
Author(s):  
Przemyslaw Wielgat ◽  
Katarzyna Niemirowicz-Laskowska ◽  
Agnieszka Z. Wilczewska ◽  
Halina Car

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.


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