Separation of human IgA1 and IgA2 using jacalin-agarose chromatography.
A lectin isolated from the tropical jackfruit, jacalin, previously reported to precipitate human immunoglobulin A (IgA), and conjugated to agarose was used to separate the two subclasses of IgA from secretions. Jacalin-agarose binds specifically to the D-galactose moiety of IgA1 but not to IgA2 which has a different carbohydrate content and structure. IgA2 passed through the jacalin-agarose column and was collected in the void volume. IgA1 was eluted from the lectin by 0.8 M galactose. Of a representative diluted anti-alpha chain-purified colostral IgA preparation containing 50.2 micrograms IgA1 and 55.8 micrograms IgA2, 40.3 micrograms IgA1 (80.3% of the original) and 49.6 micrograms IgA2 (88.9%) was collected following jacalin-agarose chromatography. The jacalin-purified IgA1 fraction contained 8.0% IgA2 and the IgA2 fraction contained no IgA1. In addition, the IgA1 and IgA2 fractions had naturally occurring antibody activity to a normal oral bacterium. The method is easy, reproducible and specific and has many applications to mucosal immunological investigations.
D002847:Chromatography, Agarose / Q000379:methods*; D002850:Chromatography, Gel / Q000379:methods*; D003126:Colostrum / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D005779:Immunodiffusion; D007071:Immunoglobulin A, Secretory / Q000032:analysis / Q000145:classification / Q000302:isolation & purification*; D037102:Lectins; D010306:Parotid Gland / Q000378:metabolism; D037121:Plant Lectins; D012463:Saliva / Q000032:analysis
D007071:Immunoglobulin A, Secretory; D037102:Lectins; D037121:Plant Lectins; C043696:jacalin