Fungal β-trefoil trypsin inhibitors cnispin and cospin demonstrate the plasticity of the β-trefoil fold
Fungal β-trefoil trypsin inhibitors cnispin and cospin demonstrate the plasticity of the β-trefoil fold
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DOI：
10.1016/j.bbapap.2014.07.004
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发表时间：
2014-10-01
影响因子：
3.2
通讯作者：
Sabotic, Jerica
中科院分区：
文献类型：
--
作者：
Caglic, Petra Avanzo;Renko, Miha;Sabotic, Jerica
新近发现的真菌蛋白水解酶抑制剂cnispin(来自星状伞)和cospin(来自灰冠藻)都是高度专一性的三叶蛋白。共旋蛋白的反应位点残基Arg27位于Beta 2-Beta 3环上。我们在这里表明，蛇床子素中的反应位点残基是Lys127，位于β11-β12环上。蛇床子素是一种底物样的抑制物，而β11-β12环是另一个被招募来抑制丝氨酸蛋白酶的β-三叶折叠环。通过对COSPIN和CNISPIN中的β2-β3和β11-β12环中的P1残基进行定点突变，已经设计出了对胰蛋白酶和糜蛋白酶具有不同特异性的蛋白酶抑制剂。通过在cnispin的β2-β3环和cnispin的β11-β12环中引入第二个特定位点残基，制备了胰酶或胰酶和胰凝乳酶的双头抑制剂。这些结果表明，蘑菇中的β-三叶式蛋白酶抑制剂具有广泛的可塑性，可以利用环来抑制蛋白酶。(C)2014爱思唯尔B.V.保留所有权利。
The recently identified fungal protease inhibitors cnispin, from Clitocybe nebularis, and cospin, from Coprinopsis cinerea, are both beta-trefoil proteins highly specific for ttypsin. The reactive site residue of cospin, Arg27, is located on the beta 2-beta 3 loop. We show here, that the reactive site residue in cnispin is Lys127, located on the beta 11-beta 12 loop. Cnispin is a substrate-like inhibitor and the beta 11-beta 12 loop is yet another beta-trefoil fold loop recruited for serine protease inhibition. By site-directed mutagenesis of the P1 residues in the beta 2-beta 3 and beta 11-beta 12 loops in cospin and cnispin, protease inhibitors with different specificities for trypsin and chymotrypsin inhibition have been engineered. Double headed inhibitors of trypsin or trypsin and chymotrypsin were prepared by introducing a second specific site residue into the beta 2-beta 3 loop in cnispin and into the beta 11-beta 12 loop in cospin. These results show that beta-trefoil protease inhibitors from mushrooms exhibit broad plasticity of loop utilization in protease inhibition. (C) 2014 Elsevier B.V. All rights reserved.