Purification of a receptor for formaldehyde-treated serum albumin from rat liver.
A membrane-associated receptor involved in a specific uptake of formaldehyde-treated serum albumin (f-Alb) was purified from rat livers by Triton X-100 solubilization of a 105,000 X g membrane preparation and affinity chromatography on an f-Alb-Sepharose column. The purified receptor exhibited Mr = 125,000, consisting of two noncovalently linked glycoprotein components with Mr = 53,000 and Mr = 30,000, respectively. Incubation of 125I-receptor with f-Alb, but not with native albumin, resulted in a marked shift of pI value from 5.9 to 5.1, reflecting the presence of a specific ligand-receptor interaction. The receptor incorporated into liposomes displayed a saturable binding to 125I-f-Alb and the binding was effectively replaced by the presence of unlabeled f-Alb, with binding parameters being similar to those obtained from 125I-f-Alb binding to the sinusoidal liver cell membrane (Horiuchi, S., Takata, K., and Morino, Y. (1985) J. Biol. Chem. 260, 475-481). Reaction of anti-f-Alb receptor antibody with extracts of sinusoidal cells resulted in a specific precipitation of two proteins whose molecular weights were identical to those for the purified receptor. The anti-receptor IgG fraction effectively blocked 125I-f-Alb binding to the sinusoidal cell membranes. These results indicate that the purified protein represents the membrane-associated receptor which is presumably involved in a specific uptake of this ligand from the circulation.
Horiuchi
S
S
Takata
K
K
Morino
Y
Y
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity; D003208:Concanavalin A; D003902:Detergents; D005557:Formaldehyde / Q000378:metabolism*; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008970:Molecular Weight; D017830:Octoxynol; D011092:Polyethylene Glycols; D051381:Rats; D011919:Rats, Inbred Strains; D017457:Receptors, Albumin; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism*
D003902:Detergents; D017457:Receptors, Albumin; D011956:Receptors, Cell Surface; C044105:formaldehyde-serum albumin; C044106:formaldehyde-serum albumin receptor; D003208:Concanavalin A; D005557:Formaldehyde; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; D017830:Octoxynol