Method for the isolation of biologically active monomeric immunoglobulin A from a plasma fraction.
A purification method for immunoglobulin A (IgA) yielding monomeric IgA with a purity of over 97% has been developed. This procedure uses ethanol-precipitated plasma (Cohn fraction III precipitate) as the starting material and includes heparin-Sepharose adsorption, dextran sulfate and ammonium sulfate precipitation, hydroxyapatite chromatography, batch adsorption by an anion-exchange matrix and gel permeation. Additional protein G Sepharose treatment leads to an IgA preparation of greater than 99% purity. The isolated IgA presented with an IgA subclass distribution, equivalent to IgA in unfractionated plasma, and was biologically active, as was shown by its ability to down-modulate Haemophilus influenzae-b-induced IL-6 secretion of human monocytes.
Leibl
H
H
Immuno AG, Department of Immunological Research, Vienna, Austria.
Tomasits
R
R
Wolf
H M
HM
Eibl
M M
MM
Mannhalter
J W
JW
D011232:Chemical Precipitation; D002845:Chromatography / Q000379:methods; D002850:Chromatography, Gel; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D000431:Ethanol; D006193:Haemophilus influenzae; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D015850:Interleukin-6 / Q000378:metabolism; D046911:Macromolecular Substances; D009000:Monocytes / Q000378:metabolism
D007070:Immunoglobulin A; D015850:Interleukin-6; D046911:Macromolecular Substances; D000431:Ethanol; D017886:Durapatite