A structural basis for four distinct elution profiles on concanavalin A – Sepharose affinity chromatography of glycopeptides

1979 ◽  
Vol 57 (1) ◽  
pp. 83-96 ◽  
Author(s):  
Saroja Narasimhan ◽  
James R. Wilson ◽  
Eva Martin ◽  
Harry Schachter
Keyword(s):  
Affinity Chromatography ◽  
Weak Interaction ◽  
Concanavalin A ◽  
Tight Binding ◽  
Structural Basis ◽  
Con A ◽  
Mannose Residue ◽  
Terminal Residue ◽  
The Third ◽  
Profile Type

Twelve 14C-acetylated glycopeptides have been subjected to affinity chromatography on concanavalin A (Con A) – Sepharose at pH 7.5. The elution profiles could be classified into four distinct patterns. The first pattern showed no retardation of glycopeptide on the column and was elicited with a glycopeptide having three peripheral oligosaccharide chains:[Formula: see text]Such glycopeptides have only a single mannose residue capable of interacting with Con A – Sepharose; an interacting mannose residue is either an α-linked nonreducing terminal residue or an α-linked 2-O-substituted residue. The second type of profile showed a retarded elution of glycopeptide with buffer lacking methyl α-D-glucopyranoside (indicative of weak interaction with the column) and was given by glycopeptides with the structures:[Formula: see text]where R1 is either H or a sialyl residue. The third profile type showed tight binding of glycopeptide to Con A – Sepharose and elution as a sharp peak with 0.1 M methyl α-D-glucopyranoside; glycopeptides giving this pattern had the structures:[Formula: see text]where R2 is either H, GlcNAc, Gal-β1,4-GlcNAc, or sialyl-Gal-β1,4-GlcNAc. These glycopeptides all have two interacting mannose residues, the minimum required for binding to the column; one of these mannose residues must, however, be a terminal residue to obtain tight binding and sharp elution. The fourth profile type showed tight binding of glycopeptide to the column but elution with 0.1 M methyl α-D-glucopyranoside resulted in a broad peak indicating very tight binding; glycopeptides showing this behaviour had the structures:[Formula: see text]where R3 is either GlcNAc, Gal-β1,4-GlcNAc, or siaryl-Gal-β1,4-GlcNAc. Therefore it can be concluded that although a minimum of two interacting mannose residues is required for binding to Con A – Sepharose, the residues linked to these mannoses can either strengthen or weaken binding to the column.

The relationship between renin isoelectric forms and renin glycoforms

1994 ◽  
Vol 267 (1) ◽  
pp. R244-R252
Author(s):  
S. A. Katz ◽  
J. A. Opsahl ◽  
P. A. Abraham ◽  
M. J. Gardner
Keyword(s):  
Sialic Acid ◽  
Affinity Chromatography ◽  
Isoelectric Focusing ◽  
Concanavalin A ◽  
Plasma Clearance ◽  
Rat Kidney ◽  
Clearance Rates ◽  
Con A ◽  
Active Renin ◽  
The Relationship

Active renin can be separated into multiple isoelectric forms using shallow gradient isoelectric focusing and into multiple glycoforms using concanavalin A (Con A) affinity chromatography. The relationship between renin isoelectric forms and glycoforms has not been previously determined. In this study, each of three renin Con A glycoforms from rat kidney was composed of significantly different proportions of six renin isoelectric forms; glycoforms with the greatest affinity for Con A contained proportionally less of the acidic isoelectric forms than those with the least affinity for Con A. A set of compartmental models accurately predicted previously measured differential plasma clearance rates of the three renin glycoforms based on their corresponding isoelectric form proportions. We conclude that 1) each Con A renin glycoform is composed of significantly different proportions of isoelectric forms, and 2) the different proportions of isoelectric forms found in Con A glycoforms are sufficient to account for the differential renin plasma clearance rates demonstrated previously for renin glycoforms in the rat. These data suggest that the isoelectric and glycoform heterogeneity of active renin are, in fact, closely related and may result from variable and interrelated mannose (Con A affinity) and sialic acid (charge) attachments to renin.

Unique binding pattern to concanavalin A lectin of glycoprotein hormones alpha-subunit hypersecreted by non-functioning pituitary adenomas

1997 ◽  
pp. 709-714
Author(s):  
C Asteria ◽  
L Persani ◽  
M Ferrari ◽  
P Beck-Peccoz
Keyword(s):  
Affinity Chromatography ◽  
Postmenopausal Women ◽  
Concanavalin A ◽  
Pituitary Adenomas ◽  
Chromatographic Behavior ◽  
Binding Pattern ◽  
Lectin Affinity Chromatography ◽  
Con A ◽  
Chronic Uremia ◽  
Non Functioning Pituitary Adenomas

This study analyzed the structural differences of the carbohydrate chains of circulating free alpha-submit (alpha-SU) hypersecreted in various non-tumoral (primary hypothyroids, postmenopausal women, patients with chronic uremia, normal fetuses) and tumoral (gut carcinoids, TSH-, GH- and pure alpha-secreting pituitary adenomas) clinical conditions. Carbohydrate structures of free alpha-SU were investigated by means of lectin affinity chromatography using Concanavalin A (Con-A), which allows the separation of free alpha-SU in three different fractions (unbound = UB, weakly bound = WB and firmly bound = FB) depending on the nature and maturation of glycosylated chains. The concentrations of alpha-SU in serum and in Con-A fractions were measured by a sensitive and specific IRMA. Free alpha-SU hypersecreted from postmenopausal women, primary hypothyroids, and patients with chronic uremia showed similar binding patterns to Con-A, the percentage of UB fractions (UB: 44.5 +/- 1.9%, 39.5 +/- 3.8%, 48.2 +/- 5.6% respectively) being higher than both WB and FB fractions (WB: 33.2 +/- 1.4%, 30.7 +/- 4.6%, 28.5 +/- 2.1%; FB: 22.3 +/- 0.7%, 29.8 +/- 6.6%, 23.3 +/- 4.2% respectively). In normal fetuses the amount of UB fraction was very high (UB: 70.7 +/- 5.4%). Free alpha-SU from patients with TSH- and GH-secreting adenomas showed a binding pattern to Con-A significantly different from that observed in postmenopausal women taken as controls, the WB fractions being significantly higher (WB: 56.9 +/- 16.8% and 71 +/- 12.4% respectively, P < 0.001). A typical pattern of elution on Con-A, characterized by a prevalence of immature alpha-SU molecules eluted in the FB fraction, was found in patients with pure alpha-secreting adenomas. This chromatographic behavior was significantly different from that seen in the controls, as well as in other pituitary tumors and in gut carcinoids (FB: 41.8 +/- 5.0%, 22.3 +/- 0.7%, 16.8 +/- 6.6%, 10.6 +/- 2.0% respectively). Moreover, in these latter patients the pattern of free alpha-SU binding was exactly the opposite of that observed in pure alpha-secreting adenomas, with a prevalence of mature alpha-SU molecules (UB: 59.1 +/- 4.4 vs 18.3 +/- 7.2%). In conclusion, our data on Con-A affinity chromatography clearly demonstrate that carbohydrate branching of circulating free alpha-SU varies in patients with pituitary adenomas as compared with patients with gut carcinoids or other non-tumoral conditions. Moreover, the finding of a greater proportion of circulating free alpha-SU forms that firmly bind to Con-A in patients with pure alpha-secreting adenomas, seems to be pathognomonic of non-functioning pituitary adenomas.

scholarly journals THE EFFECT OF TOASTING, DRY UREA TREATMENT AND SPROUTING ON SOME THERMOSTABLE TOXIC FACTORS IN THE JACKBEAN SEED

2021 ◽  
Vol 25 (1) ◽  
pp. 36-39
Author(s):  
B. O. ESOUN ◽  
A. B. I. UDEDIBIE ◽  
C. R. CARLINI
Keyword(s):  
Concanavalin A ◽  
Crude Protein ◽  
Appreciable Effect ◽  
Con A ◽  
Feed Ingredient ◽  
Urea Treatment ◽  
The Third ◽  
Toxicological Studies ◽  
Ruminant Animals ◽  
Toxic Factors

Raw unprocessed jackbean seed contains 26 – 32% crude protein and also toxic elements most of which are thermostable, which limit its use as feed ingredient for livestock especially non-ruminant animals. Raw jackbean seeds were divided into three batches. One batch was ground and toasted, the second, batch was ground raw and mixed with 2% of its weight of dry area and allowed to stand for 11days. The third batch was sprouted for four days and later ground into meal. Toxicological studies on the batches of the jackbean meals were conducted for concanavalin A (Con A) and canatoxin in jackbean seed, while sprouting was effective in detoxifying concanavalin A (Con A) and canatoxin but not very effective in detoxifying the urease activity in jackbean seed. Toasting alone did not have appreciable effect on these toxic factors

Fractionation of large glycopeptides of human teratocarcinoma-derived cells by concanavalin A – Sepharose chromatography

1980 ◽  
Vol 58 (4) ◽  
pp. 281-286 ◽  
Author(s):  
Maija-Liisa Rasilo
Keyword(s):  
Concanavalin A ◽  
Gel Filtration ◽  
Neuraminic Acid ◽  
Void Volume ◽  
Con A ◽  
The Third ◽  
Large Size

Human teratocarcinoma derived cells, line PA 1, were labeled with radioactive monosaccharides and subsequently digested with pronase. Large sized glycopeptides (fraction A) were isolated by gel filtration on Bio-Gel P-10. Their chromatography on concanavalin A – Sepharose gave three subfractions, two of which were eluted with a sugar-free buffer and the third with 10 mM α-methyl mannoside. The first subfraction (fraction A – Con A Ia) incorporated label from [3H]galactose and [3H]glucosamine and contained the largest components of fraction A. The second and the third subfractions (fractions A – Con A Ib and A – Con A II) were glycopeptides which incorporated label from tritiated fucose, mannose, galactose, and glucosamine. Even these molecules were of large size eluting partially at the void volume from Bio-Gel P-60. The glycopeptides of fraction A – Con A Ib contained mannose, fucose, galactose, N-acetylglucosamine, and N-acetylgalactosamine. Fucose and galactose residues occupied ultimate or penultimate positions at the nonreducing termini of the oligosaccharides. N-Acetyl-neuraminic acid, too, was present in the glycopeptides of fraction A.

Effects of concanavalin A on developing ganglion cells in the retina of chick embryos

Development ◽  
1981 ◽  
Vol 65 (1) ◽  
pp. 27-39
Author(s):  
K. Meller
Keyword(s):  
Cell Death ◽  
Concanavalin A ◽  
Ganglion Cells ◽  
Positional Information ◽  
Chick Embryos ◽  
Con A ◽  
The Third ◽  
Receptor Sites ◽  
Retinal Neurogenesis ◽  
Natural Cell

The administration of concanavalin A (Con A) (50–200 µg/egg) to chick embryos between the third and the seventh day of incubation has the following effects on the retina: (1) Con A causes the degeneration of a large number of ganglion cells and consequently the layer that should be formed by these cells is not present or is constituted only by a small number of ganglion cells. (2) The lectin seems to be effective only when it is administered during the postmitotic phase of the ganglion cells. (3) The degenerated cells are phagocytosed by the Müller cells in a manner similar to that occurring during the natural cell death in normal retinal development. (4) The differentiation of other retinal elements (photoreceptors, bipolar, amacrine and Müller cells) is not affected by the lectin administration. (5) The administration of Con A in later stages of development, even at ten times higher dosages (2000 µg/egg), fails to affect retinal neurogenesis. It is suggested that Con A binding to receptor sites of the cell membrane affects the distribution or mobility of surface components producing an alteration in the mechanism by which the developing cells regulate positional information during retinal neurogenesis.

Concanavalin A-induced Aggregation of Human Blood Platelets

1975 ◽  
Vol 33 (02) ◽  
pp. 354-360 ◽  
Author(s):  
Heinrich Patscheke ◽  
Reinhard Brossmer
Keyword(s):  
Concanavalin A ◽  
Binding Capacity ◽  
Specific Binding ◽  
Blood Platelets ◽  
Residual Effect ◽  
Independent Effect ◽  
Con A ◽  
Experimental Conditions ◽  
Main Effect ◽  
Induced Aggregation

SummaryConcanavalin A (CON A) causes platelets to aggregate. A Ca++-independent effect of CON A could be separated from a main effect which depends on Ca++. The main effect probably is a consequence of the CON A-induced platelet release reaction and therefore is platelet-specific. The weak residual effect observed in the presence of Na2EDTA may be due to a similar mechanism as has been demonstrated for CON A-induced aggregations of several other normal and malignant transformed animal cells.Na2EDTA did not inhibit the carbohydrate-specific binding capacity of CON A. Therefore, Na2EDTA appears not to demineralize the CON A molecules under these experimental conditions.α-methyl-D-glucoside inhibits the Ca++-independent as well as the Ca++-dependent effect of CON A.Pretreatment by neuraminidase stimulated the platelet aggregation induced by CON A. It is possible that removal of terminal sialic acid residues makes additional receptors accessible for the binding of CON A.

Structural Basis of Functional Mimicry between Carbohydrate and Peptide Ligands of Con A

2000 ◽  
Vol 272 (3) ◽  
pp. 843-849 ◽  
Author(s):  
Deepti Jain ◽  
Kanwal J. Kaur ◽  
Manisha Goel ◽  
Dinakar M. Salunke
Keyword(s):  
Peptide Ligands ◽  
Structural Basis ◽  
Con A

scholarly journals Visualization of intracellular concanavalin A binding sites in retinal photoreceptors.

1978 ◽  
Vol 26 (10) ◽  
pp. 822-828 ◽  
Author(s):  
I Nir
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Photoreceptor Cells ◽  
Con A ◽  
Thin Sections ◽  
Glycol Methacrylate ◽  
Outer Segments ◽  
Retinal Photoreceptors ◽  
Carbohydrate Components ◽  
The Relationship

Localization of carbohydrate components in retinal photoreceptor cells and membranes was studied. Frog and rat retinas were fixed with glutaraldehyde and embedded in glycol methacrylate or in a mixture of glycol methacrylate, glutaraldehyde and urea. Thin sections were incubated with ferritin-labeled concanavalin A (F-Con A) and stained with osmium vapors. Intensive binding was observed in both rod and cone outer segments. In the rod inner segment, differential binding of F-Con A was demonstrated. While numerous ferritin granules were observed in the myoid zone, only a few were seen in the ellipsoid zone, except for a local accumulation along the plasma membrane. In the rod outer segment, Con A binding sites were closely associated with the disk membranes. Ferritin granules were observed on both sides of the membranes. The relationship between the localization of Con A binding sites and the orientation of visual pigment molecules within the rod outer segments disk membranes was discussed.

Factors Influencing the Reaction of α1-Fetoprotein with Concanavalin A and Lens Culinaris Agglutinin in Crossed Affinoimmunoelectrophoresis

1992 ◽  
Vol 38 (8) ◽  
pp. 1418-1424 ◽  
Author(s):  
D Magne ◽  
N Seta ◽  
D Lebrun ◽  
G Durand ◽  
D Durand
Keyword(s):  
Concanavalin A ◽  
Lens Culinaris ◽  
Biological Fluids ◽  
Con A ◽  
Cellular Origin ◽  
Lens Culinaris Agglutinin ◽  
Lentil Lectin ◽  
Wide Range ◽  
Minimal Quantity ◽  
Antibody Ratio

Abstract Concanavalin A (Con A) and lentil lectin (LCA) analysis of alpha-fetoprotein (AFP) glycosylation heterogeneity is used in a variety of clinical situations. We studied the influence of analytical conditions on the separation of AFP glycoforms by using lectin-crossed affinoimmunoelectrophoresis, regardless of the AFP concentration, which can vary over a wide range in biological fluids. We defined the optimal concentration of Con A (2 g/L) and LCA (0.35 g/L) in the first-dimension gel, together with the optimum antigen (AFP)/antibody ratio in the second-dimension gel. The presence of protein in the diluent used for AFP samples was found to change the shape of crossed affinoimmunoelectrophoresis patterns without changing the percentage composition of AFP fractions. The within-run CV was less than 4% for both lectins, and the between-run CV was less than 6.3%. The minimal quantity of AFP that provided a visible pattern with both lectins was 4 ng, corresponding to 50 microL of an 80 micrograms/L AFP sample. These technical conditions allow the cellular origin of AFP to be determined, regardless of the concentration in the sample. Typical AFP lectin patterns of secreting tumors are compared with fetal and cord serum AFP.

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