Identification of an insulin‐like growth factor‐binding protein in human cerebrospinal fluid with a selective affinity for IGF‐II

FEBS Letters

Binoux, Michel¹  Segovia-Quinson, Berta¹  Seurin, Danielle¹  Hossenlopp, Paul¹ 

[1] INSERM U 142, Hôpital Trousseau, 75571 Paris Cedex 12, France

关键词: (Cerebrospinal fluid) Insulin-like growth factor Insulin-like growth factor-binding protein Western blotting Chromatofocusing Competitive binding assay;   

DOI  :  10.1016/0014-5793(86)81065-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Human cerebrospinal fluid (CSF) has been found to contain several different molecular forms of IGF-specific binding proteins (BPs). Qualitatively, they are similar to those present in serum, although their relative proportions are very different, as well as to those present in the culture media of brain tissue from which these BPs presumably arise. One particular form of BP is predominant in CSF. It has an M _r of 34 000, as estimated by SDS-polyacrylamide gel electrophoresis followed by transfer onto nitrocellulose, and an isoelectric point around 5.0 based on chromatofocusing. It has a selective affinity for IGF-II (~4 × 10¹⁰ M⁻¹) as shown by competitive binding experiments in which biosynthetic IGF-I was about 40-times less potent than native IGF-II in displacing ¹²⁵I-labelled IGF-II. These findings are in agreement with the preponderance of IGF-II in nervous tissue and in CSF and suggest that this BP plays an important role in the interaction of IGF-II with its target cells.

【 授权许可】

Unknown