Separation of right-side-out-oriented subfractions from purified thymocyte plasma membranes by affinity chromatography on concanavalin A-sepharose

A method is described for the subfractionation of plasma membranes from thymus lymphocytes by means of affinity chromatography on concanavalin A-Sepharose. Thymus lymphocytes were disrupted by nitrogen cavitation, microsomal membranes isolated by differential centrifugation, and plasma membranes purified from microsomes by sucrose gradient ultracentrifugation. Plasma membranes were highly purified as indicated by marker enzymes and chemical analysis. To obtain membrane preparations suited for lectin-dependent affinity chromatography, sucrose was removed slowly by gradient dialysis. Plasma membranes were then equilibrated for 20 min at 4°C with concanavalin A-Sepharose, which allowed the separation of membranes into a fraction eluting freely (MF1) and a second fraction binding to the affinity absorbent (MF2), with a total recovery of about 90%. Increasing the temperature or binding time did not alter the fractionation of the plasma membrane into the two subfractions. Fractionation required the binding of matrix-bound concanavalin A to plasma membrane binding sites. Both plasma membrane subfractions proved to have preserved their original orientation (right-side out). The method described is suited to isolate different domains of the lymphocyte plasma membrane.     

Frontal affinity chromatography of ovalbumin glycoasparagines on a concanavalin A-sepharose column. A quantitative study of the binding specificity of the lectin

The interactions of Sepharose 4B-immobilized concanavalin A (ConA) with 10 glycoasparagines derived from ovalbumin were investigated quantitatively by frontal affinity chromatography. In this method, a carbohydrate solution is applied continuously to a ConA-Sepharose column and the retardation of the elution front is measured as a parameter of the strength of the interaction. The dissociation constant (Kd) for each saccharide with ConA can be determined. An analysis of the binding of p-nitrophenyl-alpha,D-mannoside has shown that the binding properties of ConA do not change essentially after immobilization on Sepharose 4B. Each of the ovalbumin glycoasparagines was labeled with tritium by the reductive methylation method for analysis. A comparison of the Kd values obtained showed that the binding of ConA varies considerably with very slight structural differences of the glycosyl chain. The results suggest that ConA recognizes a specific glycosyl chain structure, Man alpha 1-6(Man alpha 1-3)Man, in which at least one hydroxyl group at the C-3 position of C-6-linked mannose should be free. The glycoasparagines containing this structure bound strongly to ConA-Sepharose with dissociation constants below 3.4 X 10(-7) M.     

Purification and chemical characterization of polysaccharides obtained from Lampteromyces japonicus by concanavalin A-sepharose affinity chromatography

Two classes of neutral polysaccharide which could not be separated from each other by conventional methods were isolated from the fungus, Lampteromyces japonicus, by affinity chromatography using concanavalin A-Sepharose. The polysaccharide retained on the concanavalin A-Sepharose column was eluted with 0.05 M methyl alpha-D-mannopyranoside and appeared to be alpha-mannan, while that which passed through the column was virtually all beta-glucan. Both polysaccharides were subjected to Smith-type degradation, methylation, acetolysis and glucosidase treatment. The results indicated that the alpha-mannan contained predominantly alpha-(1 leads to 2)-linked side chains branching from an alpha-(1 leads to 6)-linked backbone at the (1 leads to 2,6)-linked mannopyranosyl residues. Galactose was attached to approximately one-quarter of the non-reducing mannose terminals. The beta-glucan seemed to contain mainly (1 leads to 6)-linked side chains branching from a (1 leads to 3)-linked backbone at the (1 leads to 3,6)-linked glucopyranosyl residues.     

Detection of HBs antigen with latex particles coated with human antibody prepared by affinity chromatography on concanavalin A-sepharose.

Human HBs antibody was isolated by affinity chromatography on HBs antigen absorbed to concanavalin A linked to Sepharose 4B. When a human anti-HBs immunoglobulin preparation obtained by Cohn's cold ethanol fractionation method was used as a starting material, the antibody was concentrated about 10 times in terms of the passive hemagglutination titer with a recovery rate higher than 50%. Latex particles coated with human anti-HBs antibody thus prepared were proved to be useful in detecting HBs antigen in human blood samples. In its sensitivity and in rapidity of its performance, the antibody-coated latex agglutination test seems to be superior to conventional immunodiffusion techniques.     

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

Twelve 14C-acetylated glycopeptides have been subjected to affinity chromatography on concanvalin 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: (abstract:see text). Such glycopeptides have only a single mannose residue capable of interacting with Con A--Sepharose; an interacting mannose residue is either an alpha-linked nonreducing terminal residue or an alpha-linked 2-O-substituted residue. The second type of profile showed a retarded elution of glycopeptide with buffer lacking methyl alpha-D-glucopyranoside (indicative of weak interaction with the column) and was given by glycopeptides with the structures: (abstract: 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 alpha-D-glucopyranoside; glycopeptides giving this pattern had the structures: (abstract: see text) where R2 is either H, glcNAc, Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-GlcNAc. These glycopeptides all have two interacting mannose residues, the mimimum 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 alpha-D-glucopyranoside resulted in a broad peak indicating very tight binding; glycopeptides showing this behaviour had the structures: (abstract: see text) where R3 is either GlcNAc,Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-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.     

Purification and chemical characterization of polysaccharides obtained from Lampteromyces japonicus by concanavalin A-sepharose affinity chromatography

Two classes of neutral polysaccharide which could not be separated from each other by conventional methods were isolated from the fungus, Lampteromyces japonicus, by affinity chromatography using concanavalin A-Sepharose. The polysaccharide retained on the concanavalin A-Sepharose column was eluted with 0.05 M methyl α-d-mannopyranoside and appeared to be α-mannan, while that which passed through the column was virtually all β-glucan.Both polysaccharides were subjected to Smith-type degradation, methylation, acetolysis and glucosidase treatment. The results indicated that the α-mannan contained predominantly α-(1 → 2)-linked side chains branching from an α-(1 → 6)-linked backbone at the (1 → 2,6)-linked mannopyranosyl residues. Galactose was attached to approximately one-quarter of the non-reducing mannose terminals. The β-glucan seemed to contain mainly (1 → 6)-linked side chains branching from a (1 → 3)-linked backbone at the (1 → 3,6)-linked glucopyranosyl residues.     

Separation of oligosaccharides containing terminal alpha-linked galactose residues by affinity chromatography on Griffonia simplicifolia I bound to concanavalin A-sepharose

The seeds of Griffonia simplicifolia contain a family of five isolectins (GS-I) (L. A. Murphy and I. J. Goldstein (1977) J. Biol. Chem. 252, 4739-4742) that bind with high affinity to glycoconjugates containing terminal nonreducing alpha-linked galactose residues. Here, we report that GS-I itself is bound via its high mannose-type, Asn-linked sugar chains to immobilized concanavalin A (Con A-Sepharose). The GS-I in the GS-I-Con A-Sepharose complex retains its ability to bind glycoconjugates containing terminal alpha-linked galactose residues. This convenient method to immobilize GS-I is rapid and quantitative. We have exploited this affinity system to separate oligosaccharides based on their number of terminal alpha-linked D-galactose residues.     

LM fibroblast plasma membrane subfractionation by affinity chromatography on Con A-sepharose

Affinity chromatography was used to determine the heterogeneity and orientation of plasma membrane vesicles isolated from LM fibroblasts subjected to Dounce homogenization. Two plasma membrane subfractions were obtained by Con A-Sepharose affinity chromatography of LM fibroblast plasma membranes prepared by Dounce homogenization. The desmosterol-phospholipid molar ratio, the phospholipid composition, and the phospholipid fatty acid composition were almost identical between the two fractions. However, the lipid to protein ratio was almost 2-fold greater in the nonadherent fraction A. The binding of fluorescein-concanavalin A was the same in both fractions indicating a right-side-out orientation of the vesicles. Similarly the asymmetric distribution of phosphatidylethanolamine in both membrane fractions was the same. In contrast, sialic acid content, 5′-nucleotidase activity, and (Na⁺ + K⁺)-ATPase activity were 47%, 3.7-fold, and 2.5-fold greater, respectively, in the nonadherent, lipid-rich fraction A. Structural properties of the two membrane fractions determined by fluorescence polarization and Arrhenius plots of trans-parinaric acid fluorescence were similar. These results indicate that concanavalin-A affinity chromatography separates two membrane fractions differing in sialic acid content, lipid content, and enzyme profile but having the same right-side-out orientation.     

Fractionation of human low density lipoprotein by column chromatography.

We have devised a method to fractionate low density lipoprotein (LDL) into subspecies by means of column chromatography. DEAE-agarose columns, 2.6 X 60 cm, were loaded with LDL (25-45 mg LDL protein) and eluted with a 0.045-0.13 M NaCl gradient. The LDL eluted over a volume of 900 ml. Specific portions of the eluted LDL, reapplied to a column identical with the original, reelute at about the same point. Altering the NaCl concentration of the elution fluid changed the elution volume. The cholesterol-protein ratio of the LDL subfractions was progressively lower in fractions eluting at higher NaCl concentrations. These results indicate the LDL is not a homogenous lipoprotein species but consists of subfractions which differ in at least charge and cholesterol content.     

Properties of thyroglobulins from normal thyroid and thyroid tumor on a concanavalin A-sepharose column

Affinity chromatography on a concanavalin A (con A)-Sepharose column is a potentially useful for the isolation of whole thyroglobulin (Tg) at least from normal thyroid tissue. In addition to being a simple procedure for the isolation of Tg, large amounts of Tg can be applied to the column and recovered in good yield with a buffer containing MeG. In gradient elution with buffer containing increasing amounts of MeG, a single but broad peak was obtained, without separation into subfractions. However, a hemagglutination-inhibition test showed that the Tg preparation eluted early from the column had less affinity for con A than the Tg preparation eluted later, suggesting a heterogeneous distribution of carbohydrate moieties among Tg preparations. When human Tg from thyroid tumor was applied to the column, tumor Tg partly passed through the column without being adsorbed. This unadsorbed Tg showed a very low affinity for lectins, con A and wheat germ agglutinin (WGA), as determined by a double diffusion reaction in agar gel. In contrast to this fraction, the Tg adsorbed on the con A-gel column showed a very strong affinity for WGA, differing from Tg of normal thyroid tissue. Therefore, tumor Tg preparation appears to have an abnormally modified carbohydrate structure, at least in part. The higher affinity for WGA (with a specificity for N-acetylglucosamine) seen in adsorbed Tg could be due to a larger amount of GlcNAc residues which bind irregularly in the carbohydrate moiety of tumor Tg.     

Fractionation of RNA from tetrahymena by affinity chromatography on poly-u-sepharose

Summary Exponential growing Tetrahymena pyriformis organisms were labelled with (³H) uridine or (³H) adenosine. The labelled RNA was extracted and isolated by affinity chromatography on poly-uridylic-acid Sepharose and further analysed by means of sucrose gradient centrifugation and RNase digestion.Experimental evidence proved the existence of RNase resistant poly adenylic-acid fragments in the RNA of Tetrahymena cells. This poly adenylic-acid segment has a sedimentation rate of 4-5 S and would be localised in the 10-12S region of the RNA which is probably the m-RNA.Supported by Stiftung Volkswagenwerk Research Grant No.112273.     

Fractionation of heparin by affinity chromatography on covalently-bound human alpha-thrombin

Commerical heparin, 135 USP units/mg, was fractionated by human α-thrombin-agarose affinity chromatography. Heparin was applied to an α-thrombin-agarose column equilibrated with 0.01 M Tris HCl (pH 7.4). Unbound heparin was washed from the column with the equilibration buffer. Bound heparin could be eluted with buffer containing 0.025 M NaCl. The specific activity of bound heparin was as great as 500 USP units/mg. Gel filtration was used to fractionate the heparin into molecular size classes. Low molecular weight heparin, with an average specific activity of 100 USP units/mg, was applied to the α-thrombin-agarose column. Gel filtration of the unbound heparin indicated that larger heparin molecules been selectively removed by the α-thrombin-agarose column. Bound heparin had a specific activity of 270 units/mg. Kinetic results of $\text{N-α-tosyl-L-glycyl-L-prolyl-L-arginine-}\text{p}\text{-nitroanilide}$ hydrolysis by α-thrombin in the presence of heparin correlated with the anticoagulant activity.     

Isolation of glycopeptides containing O-linked oligosaccharides by lectin affinity chromatography on jacalin-agarose

Jacalin is a lectin which has high specificity and affinity for the core disaccharide, 1-beta-galactopyranosyl-3-(alpha-2-acetamido-2-deoxygalactopyranoside ), in O-linked oligosaccharides. Here, it is shown that this lectin can be used for isolation of glycopeptides bearing O-linked oligosaccharides. Peptides produced by digestion of reduced and carboxamidomethylated human plasminogen or of bovine protein Z were chromatographed on a column of jacalin-agarose. Reverse-phase high-performance liquid chromatography revealed that two peptides from plasminogen and one from protein Z were eluted from the jacalin-agarose column by alpha-methylgalactopyranoside. Amino acid sequence and compositional analysis showed that both of the peptides from plasminogen consisted of residues 330-357 and that the single peptide from protein Z represented residues 385-396. These sequences contain the single known site of attachment of O-linked oligosaccharides to these proteins. The present analysis suggested that there may be a fraction of plasminogen with two sites of O-linked glycosylation. The two tryptic peptides isolated from plasminogen represented the same segment of the protein but sequence analysis showed that one peptide was modified only at Thr346, the known site of glycosylation, and the other peptide contained a modification of Ser339 as well. Results of the present study indicate that lectin affinity chromatography using jacalin-agarose can be a useful technique for isolating glycopeptides containing O-linked oligosaccharides and thereby localizing sites of attachment of these oligosaccharides.     

Purification of Meerrettich-peroxidase by means of affinity chromatography on concanavalin A-agarose]

Crude preparations of horse-radish peroxidase were purified by means of affinity chromatography on Concanavalin A-agarose. The peroxydase was bound to Concanavalin A, whereas the majority of other proteins of the preparation pass through the column. Subsequently the peroxidase was eluted by means of 1 M sucrose with high purity. The purified enzyme is convenient for the immunoenzyme technique.     

Sucrose hydrolysis using invertase immobilized on concanavalin A-sepharose

The stability and ability of yeast invertase (β-d-fructofuranoside fructohydrolase, EC 3.2.1.26) bound and covalently coupled to concanavalin A-Sepharose continuously to hydrolyse sucrose over long periods has been investigated. The immobilized preparation exhibited high resistance to heat and urea induced denaturation. A small column of the immobilized preparation could hydrolyse relatively high concentrations of sucrose almost quantitatively for more than 60 days.