A simple procedure for the isolation of human secretory IgA of IgA1 and IgA2 subclass by a jackfruit lectin, jacalin, affinity chromatography.
Jackfruit lectin, jacalin, prepared from two batches of jackfruit seeds showed a different specificity in precipitating reaction in Agarose gel with various purified immunoglobulins and secretory components. Jacalin-P, extracted from jackfruit seeds from the Philippines, reacts only with serum IgA and secretory IgA of IgA1 subclass. Jacalin-O, extracted from jackfruit seeds from Okinawa prefecture in Japan, makes a strong precipitin are with IgA1 subclass and a weak precipitin arc with IgA2 subclass of IgA2m(2) allotype, IgM, IgD and IgE. Human secretory IgA of IgA1 subclass was isolated from human milk by a single jacalin-P affinity chromatography using D-galactose as a dissociating agent. From conventionally purified human secretory IgA preparation, secretory IgA of IgA1 subclass and of IgA2 subclass were separated from each other. The former was separated as jacalin-P adsorbed fraction and the latter as jacalin-P non-adsorbed fraction by the affinity chromatography. Subclass composition of secretory IgA in human milk was determined by the affinity column and was calculated to be 70% for IgA1 and 30% for IgA2 subclass. Jacalin affinity chromatography has several advantages compared with antibody coupled affinity chromatography, notably, high capacity, inexpensiveness, and very mild extraction of IgA1 subclass.
D002846:Chromatography, Affinity / Q000379:methods; D003126:Colostrum / Q000276:immunology; D005260:Female; D006384:Hemagglutination; D006801:Humans; D005779:Immunodiffusion; D007071:Immunoglobulin A, Secretory / Q000145:classification / Q000302:isolation & purification*; D037102:Lectins; D037121:Plant Lectins; D011247:Pregnancy
D007071:Immunoglobulin A, Secretory; D037102:Lectins; D037121:Plant Lectins; C043696:jacalin