Isolation of the haemopexin‐haem receptor from pig liver cells

FEBS Letters

Gräsbeck, R.¹  Majuri, R.¹ 

[1] Minerva Foundation Institute for Medical Research, PO Box 819, 00101 Helsinki, Finland

关键词: Hemopexin receptor;    Hemopexin isolation;    Heme;    Affinity chromatography;    (Pig liver membrane);    Heme iron;    HSA;    human serum albumin;    TMBZ;    3;    3';    5;    5'-tetramethylbenzidine;    haem;    iron protoporphyrin IX;   

DOI  :  10.1016/0014-5793(86)81227-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Isolated pig liver plasma membranes interact specifically with the haemopexin-haem complex (K _d 4.4 × 10⁻⁷ M). Affinity chromatography was used to isolate a membrane component which binds this complex with high affinity. Pig serum haemopexin was first isolated by affinity chromatography on haemin-Sepharose followed by HPLC gel filtration. Liver membranes solubilized with Triton X-100 were incubated with haemin-Sepharose saturated with haemopexin, and as a control, with affinity gel lacking haemopexin. SDS-polyacrylamide gel electrophoresis of the eluted protein indicated that from the haemin-Sepharose emerglow-molecular-mass haemin-binding proteins whereas the eluate from haemopexin-haemin-Sepharose contained an additional 71 kDa protein, which did not bind free haemin. This protein appears to represent the haemo-pexin-haem receptor or a part of it. Haem from the haemopexin complex, as also free haemin, was accepted by a binder in the plasma membrane, which in gel filtration behaved like an 80 kDa molecule. This component probably represents a second functional subunit of the haemopexin-haem receptor.

【 授权许可】

Unknown