Isolation and partial chemical characterization of cell-surface glycopeptides from AS-30D rat hepatoma which possess binding sites for wheat germ agglutinin and concanavalin A

Biochemistry ◽  
1973 ◽  
Vol 12 (11) ◽  
pp. 2111-2118 ◽  
Author(s):  
David F. Smith ◽  
Giovanni Neri ◽  
Earl F. Walborg
1988 ◽  
Vol 251 (1) ◽  
pp. 269-277 ◽  
Author(s):  
T L Tuan ◽  
F Grinnell

We compared the wheat-germ agglutinin (WGA) and Ricinus communis agglutinin (RCA) binding sites of baby-hamster kidney (BHK) cells. There were 1.01 × 10(8) WGA-binding sites per cell (Kd = 0.027 nM) and 6 × 10(6) RCA-binding sites per cell (Kd = 0.014 nM). Binding of WGA or RCA to BHK cells resulted in more than 75% of the cell-surface binding sites becoming associated with the cytoskeleton (i.e. resistant to extraction with detergent), although no more than 10% of these sites were associated with the cytoskeleton before addition of the lectins. After binding of WGA to the cells, the cell surface was cross-linked so extensively that it remained intact even after detergent extraction of the treated cells, and could be observed by electron microscopy. A similar cross-linking effect did not occur after binding of RCA to cells, which may be because there were so many more binding sites for WGA than for RCA. The composition of WGA- and RCA-binding molecules was analysed by lectin affinity chromatography of metabolically radiolabelled BHK cells. We found that in the WGA-binding-molecule preparations there were eight major polypeptides, ranging in molecular mass from 93 to 340 kDa, and that the RCA-binding molecules were a subpopulation of the WGA-binding molecules. A polyclonal antibody against the 140 kDa fibronectin (FN) receptors of Chinese-hamster ovary (CHO) cells immunoblotted a 145 kDa polypeptide component in both WGA- and RCA-binding-molecule preparations. The results indicated that the 145 kDa component was present in at least two FN-receptor complexes that differed in glycosylation, only one of which was able to bind to RCA affinity columns. The oligomeric nature of the FN-receptor complex, which contained three polypeptides with molecular masses of 120-145 kDa, was demonstrated by using anti-(CHO-cell FN receptor) antibodies to immunoprecipitate extracts prepared from radioiodinated BHK cells.


1976 ◽  
Vol 72 (1) ◽  
pp. 81-88 ◽  
Author(s):  
John M. Robinson ◽  
David F. Smith ◽  
Edward M. Davis ◽  
Ellen B. Gilliam ◽  
Sylvia C. Capetillo ◽  
...  

1985 ◽  
Vol 33 (5) ◽  
pp. 384-388 ◽  
Author(s):  
A Bacic ◽  
M L Williams ◽  
A E Clarke

The nature of the surface saccharides of zoospores, "partially encysted zoospores" and cysts of the root-rotting fungus Phytophthora cinnamomi, has been examined by quantitative lectin binding studies. Zoospores bound concanavalin A (Con A), but did not bind any of a variety of other lectins tested. In contrast, both cysts and "partially encysted zoospores" bound soybean agglutinin (SBA) as well as Con A. This indicates that accessible alpha-D-glucosyl/alpha-D-mannosyl-containing glycoconjugates predominate at the zoospore surface, whereas both alpha-D-glucosyl/alpha-D-mannosyl and galactosyl and/or N-acetyl-D-galactosaminosyl residues are accessible at the surface of cysts and "partially encysted zoospores." Neither Ulex europeus lectin nor wheat germ agglutinin (WGA) bound to any of the three cell preparations, indicating the absence of accessible alpha-L-fucosyl and N-acetyl-D-glucosaminosyl residues.


1981 ◽  
Vol 91 (2) ◽  
pp. 361-372 ◽  
Author(s):  
P Pinto da Silva ◽  
M R Torrisi ◽  
B Kachar

The combined application of thin-section and critical-point-drying "fracture-label" is used to determine the pattern of distribution and partition of wheat-germ agglutinin and concanavalin A binding sites on the membrane faces of freeze-fractured exocrine and endocrine rat pancreatic cells. Whereas the exoplasmic face of plasma membrane is preferentially labeled by both lectins, the endoplasmic reticulum and nuclear envelope are strongly and uniformly labeled by concanavalin A but not by wheat-germ agglutinin. The results support current views in the glycosylation of membrane proteins and do not support the backflow of sialidated glycoproteins to the endoplasmic reticulum.


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