Localisation of the [32P]IP3 binding site on human platelet intracellular membranes isolated by high‐voltage free‐flow electrophoresis

FEBS Letters

Authi, Kalwant S.¹ 

[1] Platelet Section, Thrombosis Research Institute, Manresa Road, Chelsea, London, SW3 6LR, UK

关键词: Inositol trisphosphate;    Binding site localisation;    Human platelets;   

DOI  :  10.1016/0014-5793(92)80049-M

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This Study reports the localisation of the [³²P]IP₃ binding site on highly purified membrane fractions prepared using high-voltage free-flow electrophoresis. Binding studies on mixed membranes, carried out at 4°C, revealed a binding site with a K _d = 86 nM and β_max = 5.3 pmol/mg protein. The binding was potently inhibited by heparin. High-voltage free-flow electrophoresis was used to further purify surface and intracellular membranes. The intracellular membranes showed a 5-fold enrichment of binding sites with respect to the parent mixed membranes with the same K _d(80 nM), but the surface membranes showed an absence of binding activity. The results indicate the localisation of the IP₃ receptor on highly purified intracellular membranes.

【 授权许可】

Unknown