Isolation and characterization of BanLec-I, a mannoside-binding lectin from Musa paradisiac (banana)

Abstract

A lectin (BanLec-I) from banana (Musa paradisiac) with a binding specificity for oligomannosidic glycans of size classes higher than (Man)6GlcNAc was isolated and purified by affinity chromatography on a Sephadex G-75 column. It did not agglutinate untreated human or sheep erythrocytes, but it did agglutinate rabbit erythrocytes. BanLec-I stimulated T-cell proliferation. On size-exclusion chromatography, BanLec-I has a molecular mass of approx. 27 kDa, and on SDS/PAGE the molecular mass is approx. 13 kDa. The isoelectric point is 7.2-7.5. BanLec-I was found to be very effective as a probe in detecting glycoproteins, e.g. on nitrocellulose blots.

A Lectin Isolated from Bananas Is a Potent Inhibitor of HIV Replication

“…Proteins and Anti-HIV Compounds-BanLec was isolated from bananas by modification of previously described methods (21,22). 3 Snowdrop lectin (GNA) was isolated from crude extracts of snowdrop bulbs and purified over a mannose-agarose column as described previously (28).…”

“…It is a member of the jacalinrelated lectin family and can recognize high mannose structures (22)(23)(24). Lectins in this family are characterized by the presence of a ␤-prism 1 structure composed of three Greek Key turn motifs.…”

Food allergens

“…A banana protein, a lectin called BanLec-1 (Koshte et al, 1990), is a potent IgG4 inducing antigen, with little induction of IgG1 antibody (Koshte et al, 1992). It is therefore presumably an antigen that induces a strong type 2 T helper response.…”

Evaluation of the safety and pharmacokinetic profile of the broad spectrum antiviral lectin Griffithsin.

“…Immunogenicity of biologic drugs is a widely acknowledged issue, and our data suggest that future efforts to de-immunize GRFT by structure-guided elimination of T-cell epitopes [161,162], may be necessary before the product is used for chronic treatment of viral infection in humans. Lectins are well known for their mitogenic and agglutinating properties [149,151,179,[181][182][183] which prevent their use as therapeutics. We have addressed the mitogenicity concern by showing previously that GRFT lacks Tcell mitogenic activity [35].…”

“…Further, CVN was found to increase production in a number of cytokines. BanLec, a potent anti-HIV-1 lectin with specificity for oligomannose glycans higher than (Man)6GlcNAc, has been found to be an agglutinating agent in rabbit erythrocytes as well as a powerful murine T-cell mitogen [150,151].…”