Binding of immunoglobulins to the major progesterone-induced proteins secreted by the sheep uterus.
We examined the binding of immunoglobulins to the uterine milk proteins, the major progesterone-induced proteins secreted by uterine endometrium of pregnant ewes. Binding was ascertained by measuring binding of 125 I-immunoglobulin to uterine milk proteins that were Western or dot-blotted to nitrocellulose or were coupled to Sepharose. The magnitude of binding was greatest for sheep IgM, intermediate for sheep secretory IgA, low for human secretory and serum IgA, and barely detectable for sheep IgG. Binding of IgA and IgM to uterine milk proteins was time and concentration dependent, saturable, inhibited by high ionic strength buffers, and lost due to enzymatic destruction of the Fc portion of the immunoglobulin molecule. In conclusion, the uterine milk proteins preferentially bind IgA and IgM in a species-dependent manner. Such binding may be related to the role of these proteins in the uterus and may make the uterine milk proteins a useful tool for studying or purifying sheep immunoglobulins.
Hansen
P J
PJ
Department of Dairy Science, University of Florida, Gainesville 32611.
Newton
G R
GR
D000818:Animals; D001666:Binding Sites, Antibody; D002852:Chromatography, Ion Exchange; D005260:Female; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay; D007071:Immunoglobulin A, Secretory / Q000378:metabolism; D008894:Milk Proteins / Q000378:metabolism*; D009994:Osmolar Concentration; D010206:Papain / Q000378:metabolism; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology*; D011485:Protein Binding; D012756:Sheep; D013997:Time Factors; D014599:Uterus / Q000378:metabolism*
D007071:Immunoglobulin A, Secretory; D008894:Milk Proteins; D011374:Progesterone; D010206:Papain