Mechanism of activation of latent recombinant transforming growth factor beta 1 by plasmin.
Mechanism of activation of latent recombinant transforming growth factor beta 1 by plasmin.
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纤溶酶激活潜在重组转化生长因子β1的机理。
DOI：
10.1083/jcb.110.4.1361
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发表时间：
1990-04
影响因子：
7.8
通讯作者：
Moses, H L
中科院分区：
文献类型：
--
作者：
Lyons, R M;Gentry, L E;Purchio, A F;Moses, H L
转染类人猿pre-pro-TGF β 1 cDNA的中国仓鼠卵巢（CHO）细胞培养的培养基含有高水平的潜伏TGF β 1。TGF β 1前体的氨基末端区域分泌，可以在条件培养基中使用氨基末端肽特异性肽抗体进行免疫印迹检测。用双磺基琥珀酰亚基（BS3）对cho条件培养基进行化学交联，然后进行免疫印迹分析，表明潜伏重组TGF β 1含有裂解的氨基末端糖肽和成熟的TGF β 1多肽以非共价结合，这种结合具有潜伏期。本文提供的数据不支持一种独特的TGF β结合蛋白参与潜伏重组TGF β 1。cho条件培养基的纤溶酶处理导致TGF β竞争活性的出现。此外，对纤溶酶处理的cho条件培养基进行免疫印迹分析表明，氨基端糖肽部分降解，成熟的TGF β 1被释放。因此，潜伏的TGF β 1可能通过氨基端糖肽内的蛋白水解缺口被激活，从而导致三级结构和非共价键的破坏，从而释放出活性的成熟的TGF β 1。相比之下，潜在TGF β的酸激活似乎是由于氨基末端糖肽与成熟多肽的解离。
Medium conditioned by Chinese hamster ovary (CHO) cells transfected with the simian pre-pro-TGF beta 1 cDNA contains high levels of latent TGF beta 1. The amino-terminal region of the TGF beta 1 precursor is secreted and can be detected in the conditioned medium by immunoblotting using peptide antibodies specific for amino-terminal peptides. Chemical cross-linking of CHO-conditioned medium using bis- (sulfosuccinimidyl)-suberate (BS3) followed by immunoblot analyses indicates that latent recombinant TGF beta 1 contains both the cleaved amino-terminal glycopeptide and mature TGF beta 1 polypeptide in a noncovalent association and that this association confers latency. The data presented here do not support the involvement of a unique TGF beta binding protein(s) in latent recombinant TGF beta 1. Plasmin treatment of CHO-conditioned medium resulted in the appearance of TGF beta competing activity. In addition, immunoblot analysis of plasmin-treated CHO-conditioned medium indicates that the amino-terminal glycopeptide is partially degraded and that mature TGF beta 1 is released. Thus, activation of latent TGF beta 1 may occur by proteolytic nicking within the amino-terminal glycopeptide thereby causing a disruption of tertiary structure and noncovalent bonds, which results in the release of active, mature TGF beta 1. Acid activation of latent TGF beta, in comparison, appears to be due to dissociation of the amino-terminal glycopeptide from the mature polypeptide.