Structural analysis of the carbohydrate chain isolated from jacalin lectin

✍ Scribed by Calliope Capon; Friedrich Piller; Jean-Michel Wieruszeki; Yves Leroy; Bernard Fournet

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 419 KB
• Volume: 199
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(90)84099-g

✦ Synopsis

The seeds of the jackfruit, Armmpus intergrifoliu '-3, contain a haemagglutinating lectin called jacalin4 which was found to be a strong mitogen for human T cells and an activator for secretion of immunoglobulin Ig by B cells'. In contrast, Saxon et ~1.~ reported an inhibitor effect on B cell (Ig) production and an activation of T suppressor cells. Jacalin precipitates monomeric and polymeric monoclonal (MC) IgA, and polyclonal (PC) milk sIgA, but not MC IgA, of both m( 1) and m(2) allotypes, MC IgD, IgE, IgM, PC IgG, free secretory component, and J chain'. Recently, Hagiwara et al.' reported the interactions of jacalin with human IgA, by use of the latex-agglutination technique. This lectin preferentially bound to nonreducing a-D-galactosyl groups. Jacalin recognizes also the terminal P-D-Galp-(143)-P-o-GalpNAc group, as in the IgA,-hinge, and GalpNAc group, but not the P-D-Galp-( 1 -+4)-b-D-GlcpNAc nor P-D-Galp-(1 +6)-/?-D-GlcpNAc

group and their sialylated extensions'. The method described herein allowed us to prepare 250mg of jacalin. In the profile obtained in sodium dodecyl sulfate-poly(acrylamide)gel electrophoresis (SDS-PAGE) under reducing conditions (Fig. l), the two peaks correspond to the same peaks given by the lectin obtained by affinity chromatography on various o-galactose-containing columns'. The major peak has a mol. wt. of 15 000 and the minor peak of 18 000. The specific activity of the lectin preparation obtained by the procedure described herein was comparable to that of the material obtained by affinity chromatography.

The minimum concentration necessary to completely agglutinate a 2% suspension of human red blood cells was 180 ng. mL_'.