Ultrastructural localization of lectin-binding sites on the surface of the guinea pig conjunctival epithelium

1991 ◽  
Vol 229 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Stevan Latkovic
1975 ◽  
Vol 66 (2) ◽  
pp. 263-274 ◽  
Author(s):  
G L Nicolson ◽  
R Yanagimachi ◽  
H Yanagimachi

Receptors for Ricinus communis agglutinin I (RCAI), concanavalin A (Con A), and wheat germ agglutinin (WGA) were localized on the zonae pellucidae and plasma membranes of hamster, mouse, and rat eggs with ferritin-lectin conjugates. Intact eggs labeled with the ferritin conjugates showed dense concentrations of RCAI and WGA receptors in the outermost regions of their zonae pellucidae and sparse distributions of Con A receptors throughout the zonae. Ferritin-lectin labeling was specific, since inhibitory saccharides effectively blocked labeling. The asymmetric density of RCAI receptors across the zona was confirmed by ferritin-RCAI and fluorescein-RCAI labeling of mechanically isolated zonae pellucidae, indicating that the RCAI-binding sites are more densely distributed in the exterior zona regions. Plasma membranes of rodent eggs contained RCAI, WGA, and Con A receptors. These receptors were found to be more or less randomly distributed on surfaces of aldehyde-fixed eggs or on eggs labeled near 0 degrees C. However, eggs incubated at 25 degrees C showed aggregated WGA- and Con A-binding site distributions on their plasma membranes. This indicates that lectin-induced receptor redistribution occurs at this temperature. The possibility that plasma membrane receptor mobility is a requirement for sperm-egg fusion is discussed.


1993 ◽  
Vol 25 (6) ◽  
pp. 464-468 ◽  
Author(s):  
Mehrdad Salamat ◽  
Werner G�tz ◽  
J�rgen Werner ◽  
Rainer Merken

1978 ◽  
Vol 29 (1) ◽  
pp. 287-296
Author(s):  
I. Virtanen ◽  
A. Miettinen ◽  
J. Wartiovaara

In the present study ultrastructural localization of binding sites for 5 lectins was studied in rat liver cell surface membrane fractions. For this purpose ferritin-coupled Concanavalin A, wheat germ agglutinin, soybean agglutinin, Ricinus communis agglutinin 120 and Lotus tetragonolobus agglutinin I were used as probes for mannose, N-acetyl glucosamine, N-acetyl galactosamine, galactose and fucose moieties in glycoproteins and glycolipids. Although recent reports suggest presence of glycogroups on the cytoplasmic surface of cellular membranes ultrastructural identification of membrane surfaces in the present study indicated an asymmetric localization of lectin-binding sites exclusively on the extracellular side of the membranes.


1998 ◽  
Vol 197 (4) ◽  
pp. 305-315 ◽  
Author(s):  
B. Nico ◽  
Fabio Quondamatteo ◽  
Domenico Ribatti ◽  
Mirella Bertossi ◽  
Giangiuseppe Russo ◽  
...  

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