Salt-Soluble Lectins of Corn Grain

Abstract

Lectins extracted from com (Zea mays L.) kernel with Tris-HCI buffer pH 7.5 were isolated from the crude extract by affinity chromatography on Sepharose 6B-N-acetyl-D-galactosamine and Sepharose 6B-methyla-D-mannoside, and also by lectin affinity chromatography using concanavalin A and Lens culinaris lectin as ligands. According to preferential monosaccharide specificity, salt-soluble lectins of com seed comprise at least two distinct types: N-acetyl-D-galactosamine-interactive and mannose-interactive lectins. The extracted lectins are unstable, with a tendency to form aggregates during storage.

A Maize Lectin-Like Protein with Antifungal Activity against Aspergillus flavus

“…The actual amount of ZmCORp needed to inhibit the growth of A. flavus in kernels may be less than that used in our assay, given the high compartmentalization of lectins and other storage proteins in maize kernels (8). Our assay results may have underestimated the specific activity of ZmCORp because mannose-specific lectins, such as ZmCORp, tend to aggregate upon isolation (or expression in our case), which tends to reduce their activity (15).…”

“…The assays in which the antifungal properties of ZmCORp were investigated were conducted in the presence of up to 5.4 g of the protein (a final concentration of 18 mM), which is well within the range of the levels of lectins and other storage proteins that have been isolated from seeds. In an attempt to isolate and characterize salt-soluble lectins in maize, Jankovic et al (15) reported the isolation of two lectins, ZMA-I and ZMA-II, from maize kernels with respective yields of 26 and 16 g per kernel. The actual amount of ZmCORp needed to inhibit the growth of A. flavus in kernels may be less than that used in our assay, given the high compartmentalization of lectins and other storage proteins in maize kernels (8).…”

Dextran Raffinose Derivative Assay for Affinity Purified Corn Coleoptile Lectin

“…6. 7) Lectins in corn have been studied by Lepekhin et al 8) and in corn seeds by Jankovic et al 9) Also we have described an isolation procedure using red cell stroma to overcome the known instability of the com coleoptile lectin. 1 0) Although the hemagglutination assay used before is fairly sensitive and simple, it is rather uncertain due to concomitant large error arising from visual assessment of agglutination of the cells by lectins.…”