Physicochemical and immunohistological studies of a sulfobromophthalein- and bilirubin-binding protein from rat liver plasma membranes.

Abstract

A B S T R A C T Affinity chromatography over bilirubinagarose and sulfobromophthalein (BSP)-agarose was used to isolate two proteins, with high affinities for bilirubin and BSP, respectively, from Triton X-100-solubilized rat liver plasma membranes.

Bilirubin Blnding Activity of Cytokeratin 18 Isolated from the Porcine Liver.

“…Since the liver is the major tissue containing CK18 (22) and catabolizing bilirubin, one can expect that the binding affinity between CK18 and bilirubin has a certain biological significance. Previously a 55 kDa plasma membrane protein in the rat liver has been shown to bind bilirubin (12). Its immunological localization is very similar to that of SBP40.…”

Uptake of oleate by isolated rat adipocytes is mediated by a 40-kDa plasma membrane fatty acid binding protein closely related to that in liver and gut.

“…Sinusoidally enriched plasma membranes were prepared from rat livers as previously described (19,20). h-FABPpM was extracted from these membranes and purified by a modification (21) of our original procedure (7) involving preparative isoelectric focusing, affinity chromatography over oleate-coupled agarose, and hydrophobic interaction high-performance liquid chromatography (HPLC).…”

“…h-FABPpM was extracted from these membranes and purified by a modification (21) of our original procedure (7) involving preparative isoelectric focusing, affinity chromatography over oleate-coupled agarose, and hydrophobic interaction high-performance liquid chromatography (HPLC). The purified antigen, which was eluted as a single sharp peak corresponding to a molecular mass of 40 kDa from gel permeation HPLC columns (TSK-2000, Bio-Rad) and migrated as a single band on sodium dodecyl sulfate/polyacrylamide gel electrophoresis (NaDod-S04/PAGE), was used to prepare polyclonal monospecific antisera in rabbits as previously reported (7,20). Prior to use of the antibodies, albumin was separated from the immunoglobulin fraction by ammonium sulfate precipitation and ion-exchange chromatography over DEAE-cellulose and discarded.…”

Identification, isolation, and partial characterization of a fatty acid binding protein from rat jejunal microvillous membranes.

“…500-mg MVM proteins were solubilized with 1% (vol/vol) Triton X-100 (Sigma Chemical Co.) as previously described (22). After centrifugation at 100,000 g for 60 min, residual detergent was removed from the clear supernatant by passage over a column of Bio-Beads SM2 (BioRad Laboratories, Richmond, CA) (22 subject to gel filtration over a column of Sephadex G-100 (Pharmacia, Inc.), equilibrated with 0.1 M NaCl/l.0 mM NaHCO3, pH 7.6, as previously described (2). Elution was carried out with the same buffer at 5 ml/h.…”

“…Conversely, the antibody to the oleate binding membrane protein of rat liver was tested against the jejunal and liver fatty acid binding membrane proteins, the rat liver BSP/bilirubin binding membrane protein (22), whole rat serum, and concentrated rat liver as well as rat jejunal cytosols, prepared from the 100,000 g supernatants of the corresponding homogenates.…”