Lentil lectin

In a preliminary report, Ross et al. [40] used affinity chromatography to identify a putative bovine renal brush border Na /H exchanger. Brush border membranes were solubilized with Triton X-100 and chromatographed sequentially over lentil lectin Sepharose 4B and 5-(A-benzyl-iV-ethyl)amiloride coupled to epoxy-activated Sepharose 6B. The eluant contained 178- and 146-kDa proteins that were susceptible to Endo-F. Moreover, the eluants reacted on dot blot immunoassays with antisera to a 20-amino acid peptide of a human Na /H exchanger vide infra). The relationship between these proteins and the 66-kDa protein previously identified by the same investigators using amiloride photolabeling is presently unclear. 

Lentil lectin-Sepharose Detergent-soluble membrane proteins... 

Figure B3.1.3 An isoelectric focusing (IEF) gel, pH 3 to 10. Lane 1, 4 pg purified egg white cystatin. Lane M, broad-range pi standards trypsinogen (pi 9.3), lentil lectin-basic band (pi 8.65), lentil lectin-middle band (pi 8.45), lentil lectin-acidic band (pi 8.15), myoglobin-basic band (pi 7.35 visible as a broad band), myoglobin-acidic band (pi 6.85), human carbonic anhydrase B (pi 6.55), bovine carbonic anhydrase (pi 5.85), a-lactoglobulin A (pi 5.20), soybean trypsin inhibitor (pi 4.55), and amyloglucosidase (pi 3.50) in order shown from top of gel. The pi values of the two purified egg white cystatin isomers were determined to be 6.6 (upper band) and 5.8 (lower band). Adapted from Akpinar (1998) with permission from author.

Matsumura, K., Mori, S., Nagano, M., and Fusetani, N., Lentil lectin inhibits adult extract-induced settlement of the barnacle Balanus amphitrite, J. Exp. Zool., 280, 213, 1998. 

SDS-PAGE, had comparable settlement-inducing activity to the intact glycoprotein. Lentil lectin, a lectin that inhibits adult extract-induced settlement,101 could bind to each of the three major subunits. The authors suggest that specific sugar chains on each subunit of the protein play an important role in the settlement of B. amphitrite.100... 

Kornfeld, K., Reitman, M.-L. and Kornfeld, R. (1981). The carbohydrate-binding specificity of pea and lentil lectins. Fucose is an important determinant. Journal of Biological Chemistry, 256,6633-6640. 

Concanavalin A, lentil lectin, wheat germ lectin... 

Lentil Lectin Sepharose Wheat Germ Lectin Lectins Membrane proteins, glycoproteins, polysaccharides Pharmacia... 

Hemagglutinating activity in the common lentil (Lens culinaris or Lens esculenta) was first reported by Landsteiner and Raubitschek.439 Several laboratories have since isolated the lentil lectin in pure form, and studied its physical-chemical properties and interaction with carbohydrates.138,142,143,440 442... 

Tryptic peptide mapping of each lectin revealed half of the expected number of peptides (15-16 peptides of the expected 32-37). The lectins share 15 identical, or closely similar, tryptic peptides441 this suggests that each protein is a molecule consisting of identical halves.441 However, a unique peptide was identified for LcH-A which stained gray with ninhydrin. The amino terminal sequence of the first 25 amino acids of the a- and /1-subunits of the pea and the lentil lectins has been determined. It was found that, of the 25 residues analyzed,442a,b,c the N-terminal cc-chain of the lentil and pea lectins differed only at three positions, and the /1-chains at two positions. 

Metal analysis revealed one atom of Mn2+ and six atoms of Ca2+ associated with each 66.5 kg of protein.142 Addition of 5 mM Ca2+ and mM Mn2+ to the native lectins enhanced both hemagglutination and mannan precipitation. This indicates that either some metal loss occurred during purification, or that the metal binding-sites are never completely occupied442 (compare Refs. 300 and 301). Mn2+ stimulated the hemagglutinating activity of all lentil-lectin preparations more than did Ca2+, whereas Ca2+ promoted mannan precipitation more effectively.442 Demetallization, by dialysis against 0.1 M EDTA followed by M acetic... 

The lentil lectins are nonspecific with regard to hemagglutination of human erythrocytes,138,142 but they do exhibit a distinct species specificity. They agglutinate erythrocytes of squirrel,446 some species of rabbit,138,448 and horse,138 but not sheep,138 goat,138,448 or cow.448... 

All data normalized to D-mannose = 1.0.4F rom Ref. 123 molarity required to produce 50% inhibition of precipitation of lentil lectin with phosphonomannan or glycoprotein. From Ref. 143 minimum amounts (mg/ml) completely inhibiting 4 hemagglutinating doses of lentil lectin, x, no inhibition at 20 mg/ml. "From Ref 213 millimolarity needed to produce 50% inhibition of agglutination. 

Like the jack-bean and pea lectins, the lentil agglutinin interacted with 2-0-(2-acetamido-2-deoxy-j8-D-glucopyranosyI)-D-mannose,210 providing evidence that the lentil lectin binds to internal 2-0-substituted D-mannopyranosyl residues that occur in animal glycoproteins. 

Van Wauwe and coworkers182 studied the effect of various para-substituents on the binding of phenyl a-D-mannopyranosides to the lentil lectin. As with con A and the pea lectin, binding of p-substituted-phenyl a-D-mannopyranosides correlated fairly well with the Hammett substituent constant trH in which electron-releasing... 

Inasmuch as extensive maleylation of free amino groups did not abolish the hemagglutinating and polysaccharide-precipitating activity of the lentil lectin, it is probable that amino groups are not involved in the carbohydrate-binding site of the lectin.4473 Treatment of the lentil lectin with 1-acetylimidazole resulted in the modification of 3-5 tyrosyl and 7-17 amino groups.4473 The modified proteins had lost their hemagglutinating activity, but retained their capacity to interact with polysaccharides and to bind to erythrocytes.4473... 

In summary, the lentil lectins exhibit a carbohydrate-binding specificity similar to those of the pea lectin and con A primary specificity is towards a-D-mannopyranosyl residues (2), and secondary is to a-D-... 

Many unanswered questions remain with respect to the lentil lectins. These include the chemical relationship between the two lectins, a comparison of their carbohydrate-binding specificity, a study of the binding of furanoid sugars (for example, a- and /3-arabinofuranosides) to the lectins, and a determination of the H or O atoms of each hydroxyl group which may be involved in the binding phenomenon. There is also the question as to the size of the binding site will the lentil-lectin site be more complementary to sequences of a-D-(l— 2)-mannopyranosyl residues than is con A (compare Ref. 204) ... 

A comparative study of the hemagglutinating activities of the pea (Pisum sativum), the lentil (Lens culinaris), and the jack-bean (Canavalia ensiformis) lectins towards the erythrocytes of fourteen different species showed446 that the pea and lentil lectins were, in all instances, more active than con A. Of great interest was the finding that, among these three lectins, con A alone was completely inactive against human erythrocytes (blood group, unspecified).446... 

A mixture of lentil lectin-reactive glycoproteins from pig lymphocyte-plasma membrane was isolated by lentil lectin-Sepharose chromatography of sodium deoxycholate-solubilized membranes.445 Eighty-seven percent of the protein applied (17% of hexose) passed through unretarded, and 13% of the applied protein (83% of hexose) was bound, and eluted with methyl a-D-glucopyranoside solution. Recovery was 95% of the material applied, in contrast to the recovery in similar experiments conducted on con A-Sepharose columns (80% recovery).850 The eluate from the lentil column, which contained at least ten glycoproteins, blocked lymphocyte transformation induced by lentil or kidney-bean lectins.445... 

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