STRUCTURE OF THE PROTEINASE-INHIBITOR EGLIN-C WITH HYDROLYZED REACTIVE CENTER AT 2.0-ANGSTROM RESOLUTION
STRUCTURE OF THE PROTEINASE-INHIBITOR EGLIN-C WITH HYDROLYZED REACTIVE CENTER AT 2.0-ANGSTROM RESOLUTION
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DOI：
10.1016/0014-5793(93)81273-3
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发表时间：
1993-02-15
期刊：
影响因子：
3.5
通讯作者：
WILSON, KS
中科院分区：
文献类型：
--
作者：
BETZEL, C;DAUTER, Z;WILSON, KS
丝氨酸蛋白酶抑制剂的合成和天然抑制剂已被广泛研究。Eglin c是从水蛭水蛭中分离的一种小分子热稳定蛋白。Eglin c是一种有效的丝氨酸蛋白酶抑制剂。天然eglin及其与许多蛋白酶的复合物的三维结构是已知的。我们在这里描述的晶体结构水解eglin不绑定到蛋白酶。eglin的主体具有与已知的蛋白酶复合物非常相似的构象。然而，肽链在残基45和46之间的“易断”键处被切断，推测是由于结晶样品中存在枯草杆菌蛋白酶DY。通常构成eglin抑制环的残基在有切口的抑制剂中采取完全不同的构象，导致晶体中相邻分子之间的稳定接触。通过分子置换技术解析了结构，并将其精制至14.5%的最终R因子。
The inhibition of serine proteinases by both synthetic and natural inhibitors has been widely studied. Eglin c is a small thermostable protein isolated from the leech, Hirudo medicinalis. Eglin c is a potent serine proteinase inhibitor. The three-dimensional structure of native eglin and of its complexes with a number of proteinases are known. We here describe the crystal structure of hydrolysed eglin not bound to a proteinase. The body of the eglin has a conformation remarkably similar to that in the known complexes with proteinases. However, the peptide chain has been cut at the 'scissile' bond between residues 45 and 46, presumed to result from the presence of subtilisin DY in the crystallisation sample. The residues usually making up the inhibiting loop of eglin take up a quite different conformation in the nicked inhibitor leading to stabilising contacts between neighbouring molecules in the crystal. The structure was solved by molecular replacement techniques and refined to a final R-factor of 14.5%.