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.

Changing surface antigen and carbohydrate patterns during the development of Oesophagostomum dentatum

Parasitology ◽  
1999 ◽  
Vol 119 (5) ◽  
pp. 491-501 ◽  
Author(s):  
A. JOACHIM ◽  
B. RUTTKOWSKI ◽  
A. DAUGSCHIES
Keyword(s):  
Concanavalin A ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Soybean Agglutinin ◽  
Peanut Agglutinin ◽  
Oesophagostomum Dentatum ◽  
Periodate Treatment

Living and fixed specimen of Oesophagostomum dentatum were labelled in situ with serum antibodies or a panel of biotin- labelled lectins. Specific binding of antibodies was observed in all parasitic stages – freshly exsheathed 3rd-stage larvae (L3), 3rd- and 4th-stage (L4) larvae cultured in vitro and L3 and L4 and adults isolated from pig intestines. The shedding of the stained layer by motile larvae was inhibited by levamisole-induced paralysis. Larvae cultured in vitro exposed serum-derived proteins on their surface which could be labelled with secondary antibody directed against the respective serum donor species. While freshly exsheathed larvae were recognized by O. dentatum-positive serum only, older larvae and adults cross-reacted with serum from pigs infected with O. quadrispinulatum, a closely related species. Lectin binding varied considerably between stages. While binding was not observed in pre-parasitic stages, Concanavalin A, Soybean Agglutinin, Wheat Germ Agglutinin, Ricinus communis Agglutinin and Peanut Agglutinin bound to developing larvae in varying degrees. Dolichos biflorus Agglutinin only bound to advanced (luminal) larval stages, while adults generally displayed only weak or partial lectin binding (except with Concanavalin A and Wheat Germ Agglutinin). Ulex europaeus Agglutinin only labelled larvae derived from cultures containing 10% pig serum. Cleavage of the carbohydrate residues by sodium periodate treatment resulted in reduction of antibody binding to cultured larvae, but not to freshly exsheathed L3. Concanavalin A, Soybean Agglutinin, and Peanut Agglutinin binding was also reduced by periodate treatment, while binding of Wheat Germ Agglutinin and Ricinus communis Agglutinin was inhibited only in early L3, but not in older stages. The different lectin labelling patterns are related to the different stages of the nematode – infective, invasive, histotropic, and luminal – and may serve as a mode of adaptation for the parasite against the host's immune attack by surface glycoprotein variation, together with antigen shedding (as demonstrated by labelling of motile larvae) and a possible acquisition of host molecules at the parasite's surface. Furthermore, a possible role of this developmental variation in surface carbohydrates in parasite–parasite interactions is discussed.

scholarly journals Interaction of Azospirillum lipoferumwith Wheat Germ Agglutinin Stimulates Nitrogen Fixation

1999 ◽  
Vol 181 (13) ◽  
pp. 3949-3955 ◽  
Author(s):  
Eva Karpati ◽  
Peter Kiss ◽  
Tamas Ponyi ◽  
Istvan Fendrik ◽  
Miklos de Zamaroczy ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Gene Cluster ◽  
Binding Sites ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Side Chains ◽  
Receptor Complex ◽  
Sugar Binding ◽  
Signalling Cascade

ABSTRACT In vitro, the nitrogen fixation capability of A. lipoferum is efficiently increased in the presence of wheat germ agglutinin (WGA). A putative WGA-binding receptor, a 32-kDa protein, was detected in the cell capsule. The stimulatory effect requiredN-acetyl-d-glucosamine dimer (GlcNAcdi) terminated sugar side chains of the receptor and was dependent on the number of GlcNAcdi links involved in receptor-WGA interface. Binding to the primary sugar binding sites on WGA had a larger stimulatory effect than binding to the secondary sites. The WGA-receptor complex generated stimulus led to elevated transcription of the nifH and nifA genes and of the glnBA gene cluster but not of the glnA gene from its own promoter. There may well be a signalling cascade contributing to the regulation of nitrogen fixation.

scholarly journals Adsorption of horseradish peroxidase, ovomucoid and anti-immunoglobulin to colloidal gold for the indirect detection of concanavalin A, wheat germ agglutinin and goat anti-human immunoglobulin G on cell surfaces at the electron microscopic level: a new method, theory and application.

1977 ◽  
Vol 25 (11) ◽  
pp. 1187-1200 ◽  
Author(s):  
W D Geoghegan ◽  
G A Ackerman
Keyword(s):  
Horseradish Peroxidase ◽  
Concanavalin A ◽  
Colloidal Gold ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Indirect Detection ◽  
Electron Microscopic Level ◽  
Specific Cell ◽  
Major Protein ◽  
Electron Microscopic

A method is described for the adsorption of selected macromolecules to colloidal gold which is then used as an electron dense marker for the indirect detection of specific cell surface molecules. Membrane bound concanavalin A, which binds specific sugars on horseradish peroxidase, and wheat germ agglutinin, which binds specific sugars on ovomucoid are detected indirectly with gold labeled horseradish peroxidase and ovomucoid, respectively. Goat anti-human IgM on blood lymphocytes is detected with gold labeled rabbit anti-goat IgG. In the preparation of colloidal gold labeled proteins, the problems of flocculation of colloidal gold by proteins and nonadsorption of proteins to colloidal gold, are solved through a combination of concentration of protein and pH variable adsorption isotherms, which allows one to determine the conditions for adsorption of proteins to colloidal gold. Adsorption is pH dependent, the pH conditions correlating with the isoelectric point(s) of the major protein fraction(s); adsorption is influenced by interfacial tension, solubility and by the electrical charge on the molecules. Colloidal gold is inexpensive and preparation of a useful label is rapid, reproducible and the results easily quantitated from electron micrographs.

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