The presence of secretory component-free human colostral IgA in early colostrum.
Human secretory IgA was prepared from colostrum. Different elution diagrams from CM-cellulose were obtained depending on the time of collection of colostrum. In case of early colostrum, collected within 6 hours post partum, two IgA fractions were obtained after chromatography on CM-cellulose. Both fractions have different molecular weights and different amino acid compositions. The results obtained suggest that the first fraction is a dimer of IgA monomers containing J chain with a molecular weight of 330,000 whereas the second fraction having the molecular weight 395,000 daltons is composed of IgA dimer, J chain and SC. When colostrum collected 48 or more hours was used as a source of IgA, only the second IgA fraction was obtained. The problem of SC-free IgA immunoglobulins is discussed.
D000596:Amino Acids / Q000032:analysis; D002848:Chromatography, DEAE-Cellulose; D002942:Circular Dichroism; D003126:Colostrum / Q000276:immunology*; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007070:Immunoglobulin A / Q000032:analysis*; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D007231:Infant, Newborn; D008970:Molecular Weight; D009904:Optical Rotation; D013997:Time Factors
D000596:Amino Acids; D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory