Characterization of the binding of multiplication-stimulating activity to a receptor for growth polypeptides in chick embryo fibroblasts.
Characterization of the binding of multiplication-stimulating activity to a receptor for growth polypeptides in chick embryo fibroblasts.
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鸡胚成纤维细胞中增殖刺激活性与生长多肽受体结合的表征。
DOI：
10.1016/s0021-9258(17)40336-x
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
S. Nissley
中科院分区：
文献类型：
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作者：
M. Rechler;J. Podskalny;S. Nissley
增殖刺激活性 (MSA) 是从大鼠肝细胞系培养基中分离出来的分子量约为 10,000 的多肽家族的名称。 MSA 刺激鸡胚成纤维细胞的生长和 DNA 合成，并具有较弱的胰岛素样代谢活性。我们纯化了 MSA，并表征了“I”标记的 MSA 与鸡成纤维细胞中特定受体的结合。结合快速且可逆。在稳态下获得并根据斯卡查德绘制的竞争性结合数据是线性的。计算出 AK、4.2 X lo8 MI 的 l 和 58,000 MSA 分子/细胞的结合能力。只有未标记的 MSA 或密切相关的多肽才能竞争 MSA 示踪剂的结合。不同纯化阶段的 MSA 制剂根据其作为鸡成纤维细胞 DNA 合成刺激剂的相对活性抑制结合。 NSILA-s（不可抑制的胰岛素样活性，可溶于酸性乙醇）是一种从人血浆中纯化的多肽，其化学和生物学特性与 MSA 相似，可有效抑制 9 标记的 MSA 与鸡成纤维细胞的结合。作为 MSA 与鸡成纤维细胞结合的抑制剂，胰岛素和胰岛素原的功效分别为 MSA 的 60% 和 25%（按重量计）。 NSILA-s 还有效抑制 MSA 与大鼠肝质膜的结合，而胰岛素和胰岛素原均不抑制 MSA 与肝膜的结合，即使在高肽浓度下也是如此。因此，鸡成纤维细胞MSA受体的特异性不同于肝膜MSA受体。鸡成纤维细胞MSA受体的特异性也不同于鸡成纤维细胞和其他细胞中胰岛素受体的特异性。具体而言，MSA、NSILA-s和胰岛素原作为MSA与MSA受体结合的抑制剂比胰岛素与胰岛素受体结合的抑制剂更有效。事实上，与鸡成纤维细胞竞争MSA结合的多肽——MSA、NSILA-s、胰岛素和胰岛素原——也在相当浓度下促进鸡成纤维细胞的生长和DNA合成，这进一步支持了我们的论点，即MSA受体介导这些多肽的生长刺激。
Multiplication-stimulating activity (MSA) is the name given to a family of polypeptides with a molecular weight of approximately 10,000 that have been isolated from the culture medium of a rat liver cell line. MSA stimulates growth and DNA synthesis in chick embryo fibroblasts and has weak insulin-like metabolic activity. We have purified MSA and characterized the binding of ‘““I-labeled MSA to specific receptors in chicken fibroblasts. Binding was rapid and reversible. Competitive binding data obtained at steady state and plotted according to Scatchard were linear. AK, l of 4.2 X lo8 MI and a binding capacity of 58,000 MSA molecules/cell were calculated. Only unlabeled MSA or closely related polypeptides competed for the binding of MSA tracer. MSA preparations at different stages of purification inhibited binding in accordance with their relative activities as stimulators of chicken fibroblast DNA synthesis. NSILA-s (nonsuppressible insulin-like activity soluble in acid ethanol), a polypeptide purified from human plasma with chemical and biological properties similar to those of MSA, potently inhibited the binding of ‘9-labeled MSA to chicken fibroblasts. Insulin and proinsulin were 60 and 25% as potent as MSA by weight, respectively, as inhibitors of MSA binding to chicken fibroblasts. NSILA-s also effectively inhibited MSA binding to rat liver plasma membranes, whereas neither insulin nor proinsulin inhibited MSA binding to liver membranes even at high peptide concentrations. Thus, the specificity of the chicken fibroblast MSA receptor differed from that of the liver membrane MSA receptor. The specificity of the chicken fibroblast MSA receptor also differed from that of insulin receptors in chicken fibroblasts and other cells. Specifically, MSA, NSILA-s, and proinsulin were considerably more potent as inhibitors of MSA binding to MSA receptors than of insulin binding to insulin receptors. The fact that the polypeptides competing for MSA binding to chicken fibroblasts-MSA, NSILA-s, insulin, and proinsulin-also promoted growth and DNA synthesis in chicken fibroblasts at comparable concentrations, further supports our contention that the MSA receptor mediates growth stimulation by these polypeptides.