Insulin-like growth factor binding protein measurement: sodium dodecyl sulfate-stable complexes with insulin-like growth factor in serum prevent accurate assessment of total binding protein content by ligand blotting.
Insulin-like growth factor binding protein measurement: sodium dodecyl sulfate-stable complexes with insulin-like growth factor in serum prevent accurate assessment of total binding protein content by ligand blotting.
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胰岛素样生长因子结合蛋白测量：血清中十二烷基硫酸钠与胰岛素样生长因子的稳定复合物妨碍通过配体印迹准确评估总结合蛋白含量。
DOI：
10.1016/0003-2697(90)90390-u
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发表时间：
1990
影响因子：
2.9
通讯作者：
Ling,N
中科院分区：
文献类型：
--
作者：
Bicsak,TA;Nakatani,A;Shimonaka,M;Malkowski,M;Ling,N
The possibility that sodium dodecyl sulfate (SDS)-stable complexes of insulin-like growth factor I (IGF-I) and its binding proteins (IGF-BP) exist in rat serum has been examined by using SDS-polyacrylamide gel electrophoresis (PAGE) followed by both [125I]IGF-I ligand blotting and immunoblotting with antisera directed against either IGF-BP3 or IGF-I. While ligand blotting of rat serum only revealed free IGF-BP subunits (Mr≈ 50, 35, and 30 kDa, immunoblotting with either the IGF-BP3 antiserum or IGF-I antiserum revealed major immunoreactive bands with higher molecular weights (>110, ≈100, and ≈84 kDa). The IGF-BP3 antiserum also stained the 50-kDa form of the serum IGF-BP. Specifically stained protein bands were identified by comparison with control immunoblots incubated with normal rabbit serum. Treating the serum with 0.1 n HCl prior to electrophoresis reduced the amount of high molecular weight IGF-BP3 immunoreactive species, with a concomitant increase in the amount of the 50-kDa form. A similar result was obtained if the samples were boiled prior to electrophoresis. These data indicate that not all IGF-BP IGF complexes may dissociate under normal SDS-PAGE conditions. Therefore, data obtained by using ligand blotting alone may underestimate the amount of total IGF-BP present, especially if the mixture being analyzed also contains large amounts of IGF.
