Polymeric IgA are sulfated proteins.
The main sulfated proteins secreted by rabbit mammary gland tissue had M(r) of approximately 67 000, 63 000 and 23 000, and one component which most likely corresponded to proteoglycans had a diffuse electrophoretic mobility (M(r)200 000). The sulfate groups in the 67-63 kDa proteins were mostly linked to carbohydrates. These proteins and the 23 kDa protein were co-purified and identified to heavy chains of immunoglobulin A (IgA) and J chain, respectively. Sulfation of alpha-chains also occurred in rat mammary and rabbit lacrimal glands. We conclude that polymeric IgA which are produced by plasma cells and released in secretion fluids after transcytosis through epithelia are sulfated.
Boisgard
R
R
Institut National de la Recherche Agronomique, Station de Physiologie Animale, F-78352, Jouy-en-Josas, France.
Charpigny
G
G
Chanat
E
E
D000595:Amino Acid Sequence; D000818:Animals; D004847:Epithelial Cells / Q000378:metabolism; D007070:Immunoglobulin A / Q000737:chemistry*; D007071:Immunoglobulin A, Secretory / Q000737:chemistry*; D066298:In Vitro Techniques; D007765:Lacrimal Apparatus / Q000378:metabolism; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008894:Milk Proteins / Q000737:chemistry*; D011817:Rabbits; D051381:Rats; D011916:Rats, Inbred F344; D013431:Sulfates / Q000737:chemistry; D013462:Sulfur Radioisotopes
D007070:Immunoglobulin A; D007071:Immunoglobulin A, Secretory; D008894:Milk Proteins; D013431:Sulfates; D013462:Sulfur Radioisotopes; C034639:polymeric IgA