Concanavalin A receptors

Tunicamycin specifically inhibits cell division and pairing between the mating types of Tetrahymena pyriformis. The glycoproteins involved in this mating process have not yet been characterized, but may coincide with new, concanavalin A receptor-sites that appear during conjugation.495... 

Poo, M.-M. Robinson, K. R. Electrophoresis of concanavalin A receptors along embryonic muscle membrane. Nature 1977, 265, 602-605. 

Although DSC and other physical techniques have made considerable contributions to the elucidation of the nature of lipid-protein interactions, several outstanding questions remain. For example, it remains to be dehnitively determined whether some integral, transmembrane proteins completely abolish the cooperative gel-to-liquid-crystalline phase transition of lipids with which they are in direct contact or whether only a partial abolition of this transition occurs, as is suggested by the studies of the interactions of the model transmembrane peptides with phospholipids bilayers (see above). The mechanism by which some integral, transmembrane proteins perturb the phase behavior of very large numbers of phospholipids also remains to be determined. Finally, the molecular basis of the complex and unusual behavior of proteins such as the concanavalin A receptor and the Acholeplasma laidlawii B ATPase is still obscure (see Reference 17). 

The aggregation of bovine erythrocytes by concanavalin A is highly sensitive to the level of functionally identical concanavalin A receptors.Threshold densities of these receptors are required for aggregation to occur. 

Concanavalin A is a plant lectin from the jack bean (Canavalia ensiformis) which binds with high affinity to mannose residues of glycoproteins. Concanavalin A is known to stimulate the tyrosine kinase activity of the INSR (3-subunit with consecutive activation of kinases downstream the insulin receptor (IRS, PI 3-kinase). It is believed that Concanavalin A stimulates the activation and autophosphorylation of the INSR kinase through aggregation of the receptor, although the precise mechanism of action is unclear. 

Con A Concanavalin A COPD Chronic obstructive pulmonary disease COS Fibroblast-like kidney cell line established from simian cells CoVF Cobra venom CP Creatine phosphate Cp Caeruloplasmin c.p.m. Counts per minute CPJ Cartilage/pannus junction Cr The chemical symbol fir chromium CR Complement receptor CRl, CR2 CR4 Complement receptor types 1, 2 and 4 CR3-a Complement receptor type 3-[Pg.281]

J. Lehmann and U. P. Weitzel, Synthesis and application of a-D-mannosyl clusters as photoaffinity ligands for mannose-binding proteins Concanavalin A as a model receptor, Carbohydr. Res., 294 (1996) 65-94. 

AMPA receptors desensitize within milliseconds upon exposure to AMPA, and kainate receptors likewise upon exposure to kainate. AMPA and kainate receptors can be securely distinguished from one another by their response to two drugs, cyclothiazide and the lectin concanavalin A [10], Cyclothiazide relieves AMPA receptor desensitization without affecting kainate receptors. 

Conversely, concanavalin A relieves desensitization of kainate receptors, presumably via interaction with surface sugar chains, but has insignificant effects on AMPA receptors. 

The first allosteric modulators discovered to act on AMPA/KA receptors were the plant lectins, including concanavalin A (ConA), that block receptor desensitization, probably through binding to Y-1 inked oligosaccharides (51,52). It was soon discovered that certain benzothiazides, such as diazoxide and cyclothiazide, also act on the same allosteric site controlling non-NMDA receptor desensitization (53-55). Interestingly, ConA and cyclothiazide show high selectivity for KA and AMPA receptors, respec-... 

Mayer, M. L. and Vyklicky, L., Jr. (1989) Concanavalin A selectively reduces desensitization of mammalian neuronal quisqualate receptors. Proc. Natl. Acad. Sci. USA 86, 1411-1415. 

Taken together, these results suggest that molecular recognition of the dodecapeptide by antibodies differs from its recognition by concanavahn A, and that the immunological cross-reactivity observed in some studies does not reflect structural mimicry. That molecular recognition by concanavalin A of carbohydrates and peptides differs has also been shown in structural studies. Here, the functional molecular mimicry observed with respect to different receptors should not be assumed to imply structural mimicry—the inter-molecular interactions may differ in each case. 

Continuous stimulation with concanavalin A was considered necessary because the burst could be blunted by the addition of alpha methyl mannoside after Con A stimulation had already commenced, suggesting, that, displacement of Con A from its receptor could reverse the stimulation. The fungal metabolites, the cytochalasins, exert varied effects whereas cytochalasin B enhances the formation of O by other agents, especially particulate stimuli which can be internalized cytochalasin... 

Yahara I, Edelman GM. Restriction of mobility of lymphocyte immunoglobulin receptors by concanavalin-A. Proceedings of the National Academy of Sciences of the United States of America 1972, 69, 608-612. 

Concanavalin A (con A) has been reported to interact with specific membrane saccharide receptors and agglutinate a wide variety of transformed cells at low concentrations of the lectin without affecting the normal untransformed parent line (1,2). ... 

These same surface glycoproteins have been modeled as receptors for antibody molecules and in the binding of lectin molecules, such as concanavalin A. On the lymphocyte membrane,... 

Surface immunoglobulin receptor of human B-cell lymphoma Tumor suppressor protein p53 mAb 5.5 against the ligand-binding site ot the nicotinic acetylcholine receptor Bovine pancreatic RNase fragment concanavalin A... 

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