Distribution of concanavalin A and wheat germ agglutinin binding sites in the rat peripheral nerve fibres revealed by lectin/glycoprotein-gold histochemistry

1996 ◽  
Vol 28 (1) ◽  
pp. 7-12 ◽  
Author(s):  
S. Dolapchieva
Keyword(s):  
Peripheral Nerve ◽  
Concanavalin A ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Nerve Fibres ◽  
Rat Peripheral Nerve

scholarly journals Freeze-fracture cytochemistry: localization of wheat-germ agglutinin and concanavalin A binding sites on freeze-fractured pancreatic cells.

1981 ◽  
Vol 91 (2) ◽  
pp. 361-372 ◽  
Author(s):  
P Pinto da Silva ◽  
M R Torrisi ◽  
B Kachar
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Concanavalin A ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Freeze Fracture ◽  
Combined Application ◽  
Pancreatic Cells ◽  
Critical Point Drying

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.

scholarly journals Influence of Concanavalin A, wheat germ agglutinin, and soybean agglutinin on the fusion of myoblasts in vitro.

1975 ◽  
Vol 67 (3) ◽  
pp. 826-834 ◽  
Author(s):  
H Den ◽  
D A Malinzak ◽  
H J Keating ◽  
A Rosenberg
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Inhibitory Effect ◽  
Myoblast Fusion ◽  
Normal Serum ◽  
Specific Cell ◽  
Number Of Binding Sites

Although muscle cell fusion was shown to be an energy-requiring process, release of myoblasts from an EGTA fusion block could be accomplished with Earle's balanced salt solution (containing 1.8 mM Ca++) free of glucose or any other energy-produced metabolite. The effect of concanavalin A, abrin, and the lectins from wheat germ, soybean, and Lens culinaris on myoblast fusion was examined with synchronized myoblast cultures upon release from fusion block. At a concentration of 15 mug/ml, these lectins were found to inhibit the fusion process to the extent of 62%, 41%, 32%, 8%, and 19%, respectively. Concanavalin A inhibition could be prevented by alpha-methyl-D-mannoside. The inhibitory effect of all the lectins except abrin could be reversed by changing to the normal, serum-containing medium. The number of binding sites was 3.4 X 10(7), 6.1 X 10(7), and 1.7 X 10(6), respectively. Although myoblasts were found to have about twice as many binding sites for wheat germ agglutinin as for concanavalin A, concanavalin A was determined to be twice as effective as wheat germ agglutinin as an inhibitor of myoblast fusion. These findngs raise the possibility that specific cell surface glycoproteins may be an important factor in this process.

Analysis of surface carbohydrates of Trichobilharzia ocellata miracidia and sporocysts using lectin binding techniques

Parasitology ◽  
1991 ◽  
Vol 103 (1) ◽  
pp. 51-59 ◽  
Author(s):  
M. J. T. Gerhardus ◽  
J. M. C. Baggen ◽  
W. P. W. Van Der Knaap ◽  
T. Sminia
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Lectin Binding ◽  
Surface Coat ◽  
Peanut Agglutinin ◽  
High Concentrations ◽  
Trichobilharzia Ocellata

Miracidia and in vitro-derived primary sporocysts of the avian schistosome Trichobilharzia ocellata were studied for the expression and the characteristics of glycoconjugate moieties comprising the surface coat. Using a panel of 9 peroxidase labelled lectins, several different lectin binding sites were demonstrated on the larvae. Fixed miracidia have binding sites for 7 of the lectins; wheat-germ agglutinin binds to both the ciliated plates and the tegumental ridges between them; the other 6 lectins bind to the plates only. Three of the miracidia-binding lectins, wheat-germ agglutinin, concanavalin A and peanut agglutinin, also bind to fixed sporocysts. Since the miracidial ridges are devoid of binding sites for concanavalin A and peanut agglutinin, whereas the sporocyst tegument binds these lectins, it appears that these sites become exposed during or shortly after transformation. In saturation experiments, low concentrations of peanut agglutinin and concanavalin A are bound more avidly by sporocysts than by miracidia, indicating a higher binding affinity of the former. The two larval forms do not differ in affinity for wheat-germ agglutinin but they have different binding capacities; when offered in high concentrations, more of this lectin is bound by sporocysts than by miracidia. Lectin binding was competitively inhibited by adding the appropriate free saccharides. Live larvae showed the same lectin binding pattern as did fixed specimens. Proteinase treatment reduced lectin binding to living and, to a lesser extent, to fixed larvae, suggesting that binding sites are constituents of proteoglycoconjugates. After SDS–PAGE of extracts from miracidia and sporocysts and subsequent Western blotting, some of the lectins failed to bind glycoproteins, others reacted with an array of bands. The patterns differed among the lectins and each lectin gave different patterns for miracidia and sporocysts. The results obtained with these two lectin-binding techniques support the conclusion that stage-specific proteoglycoconjugates occur at the surface of T. ocellata larvae.

scholarly journals Receptor-mediated gonadotropin action in the ovary. Inhibitory actions of concanavalin A and wheat-germ agglutinin on gonadotropin-stimulated cyclic AMP and progesterone responses in ovarian cells

1981 ◽  
Vol 200 (1) ◽  
pp. 153-159 ◽  
Author(s):  
S Azhar ◽  
K M Menon
Keyword(s):  
Cyclic Amp ◽  
Concanavalin A ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Carbohydrate Chain ◽  
Inhibitory Effect ◽  
Dolichos Biflorus ◽  
Acetylneuraminic Acid ◽  
Ovarian Cells ◽  
Proline Incorporation

Pretreatment of ovarian cells with concanavalin A and wheat-germ agglutinin blocked the gonadotropin-induced cyclic AMP and progesterone responses and this effect was time- and concentration-dependent. Basal production of either cyclic AMP or progesterone, however, was not affected by treatment of cells with lectin. The effect of concanavalin A on gonadotropin-mediated cyclic AMP and progesterone responses was blocked by alpha-methyl D-mannoside and alpha-methyl d-glucoside. Similarly the inhibitory effect of wheat-germ agglutinin was reversed by N-acetyl-D-glucosamine. Pretreatment of ovarian cells with concanavalin A or wheat-germ agglutinin had no effect on protein synthesis in the ovary as monitored by [3H]proline incorporation studies. Concanavalin A and wheat-germ agglutinin did not affect steroid production in response to dibutyryl cyclic AMP and 8-bromo cyclic AMP, indicating that the inhibitory action of lectin was occurring at a step before cyclic AMP formation. Lectins specific for L-fucose, D-galactose and N-acetyl-D-galactosamine, gorse seed agglutinin, peanut agglutinin and Dolichos biflorus agglutinin respectively, did not interfere with gonadotropin-induced cyclic AMP and progesterone responses. The present studies suggest that gonadotropin receptors may be glycoprotein in nature or closely associated with glycoprotein structures with the carbohydrate chain containing N-acetyl-D-glucosamine, mannose and possibly N-acetylneuraminic acid.

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