Cloning and sequence determination of bovine insulin-like growth factor binding protein-2 (IGFBP-2): comparison of its structural and functional properties with IGFBP-1.
Cloning and sequence determination of bovine insulin-like growth factor binding protein-2 (IGFBP-2): comparison of its structural and functional properties with IGFBP-1.
复制标题
牛胰岛素样生长因子结合蛋白 2 (IGFBP-2) 的克隆和序列测定：其结构和功能特性与 IGFBP-1 的比较。
DOI：
10.1002/jcb.240480212
复制
发表时间：
1992
影响因子：
4
通讯作者：
Clemmons,DR
中科院分区：
文献类型：
--
作者：
Bourner,MJ;BusbyJr,WH;Siegel,NR;Krivi,GG;McCusker,RH;Clemmons,DR
胰岛素样生长因子结合蛋白 (IGFBP) 由多种细胞类型分泌，可以改变 IGF 的作用。 Mandin-Darby 牛肾 (MDBK) 细胞已被证明可分泌 34,000 Da 形式的 IGF 结合蛋白，其 N 末端序列与从大鼠 BRL-3A 细胞中纯化的 IGFBP 形式相似，最近被命名为 IGFBP-2。这些研究报告了牛 IGFBP-2 的完整氨基酸序列，并将其功能特性与人 IGFBP-1 进行了比较。该蛋白与大鼠 IGFBP-2 81% 相同。与大鼠 IGFBP-2 和人 IGFBP-1 相比，所有 18 个半胱氨酸残基的位置都是保守的。类似地，RGD 序列存在于两种蛋白质的羧基末端附近。 IGFBP-2 对 IGF-II 的亲和力高于对 IGF-I 的亲和力，并且其对两种形式 IGF 的亲和力均大于对人 IGFBP-1 的亲和力。与IGFBP-1一样，该蛋白能增强猪主动脉平滑肌细胞对IGF-I的DNA合成反应；然而，IGFBP-2 的效力要弱得多。 IGF 介导的促有丝分裂反应的最大增强效果约为 IGFBP-1 的 42%。这种增强作用取决于贫血小板血浆中所含的因子，如果从培养介质中省略该因子，IGFBP-2 就会抑制 DNA 合成。 IGFBP-2 的纯化将允许在生理测试系统中对其与其他形式的 IGFBP 进行更详细的比较。
Insulin-like growth factor binding proteins (IGFBPs) are secreted by several cell types and can modify IGF actions. Mandin-Darby Bovine Kidney (MDBK) cells have been shown to secrete a 34,000 Da form of IGF binding protein whose N-terminal sequence is similar to a form of IGFBP purified from rat BRL-3A cells that has recently been named IGFBP-2. These studies report the complete amino acid sequence of bovine IGFBP-2 and compare its functional properties with human IGFBP-1. The protein is 81% identical to rat IGFBP-2. When compared with both rat IGFBP-2 and human IGFBP-1, the positions of all 18 cysteine residues are conserved. Similarly an RGD sequence is present near the carboxyl terminus in both proteins. IGFBP-2 has a higher affinity for IGF-II than for IGF-I and its affinity for both forms of IGF is greater than for human IGFBP-1. Like IGFBP-1 the protein can enhance the DNA synthesis response of porcine aortic smooth muscle cells to IGF-I; however, IGFBP-2 was much less potent. The maximum potentiation of the IGF-mediated mitogenic response that could be achieved was approximately 42% that of IGFBP-1. This potentiation is dependent upon a factor contained in platelet poor plasma and if this factor is omitted from the incubation medium, IGFBP-2 inhibits DNA synthesis. The purification of IGFBP-2 will allow more detailed comparisons to be made between it and other forms of IGFBPs in physiologic test systems.