Binding of secretory component to protein 511, a pIgA mouse protein lacking 36 amino acid residues of the C alpha 3 domain.
Protein 511, a murine IgA protein described previously by Robinson and Appella [Proc. natn. Acad. Sci. U.S.A. 77, 4909-4913 (1980)] which lacks 36 amino acids in the C alpha 3 domain, was tested for its ability to bind to radiolabelled secretory component (125I-rat SC) and to be transported from blood to bile in the rat, a function described previously to be mediated by the poly Ig receptor (pIg R). When compared to other mouse pIgA proteins, the naturally occurring mutant protein 511 bound 125I-rat SC and was transported from blood to bile in a manner indistinguishable from wild-type pIgA protein. We conclude that the region of Fc alpha which is missing in protein 511, is not involved in mediating the binding of pIgA to the pIg R.
Switzer
I C
IC
Department of Pathology, McMaster University Faculty of Health Sciences, Hamilton, Canada.
Loney
G M
GM
Yang
D S
DS
Underdown
B J
BJ
D000818:Animals; D001646:Bile / Q000378:metabolism; D003198:Computer Simulation; D007070:Immunoglobulin A / Q000378:metabolism*; D066298:In Vitro Techniques; D051379:Mice; D008958:Models, Molecular; D009194:Myeloma Proteins / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D051381:Rats; D012635:Secretory Component / Q000378:metabolism*; D013329:Structure-Activity Relationship
D007070:Immunoglobulin A; D009194:Myeloma Proteins; D012635:Secretory Component; C034639:polymeric IgA