Heitz A, Chiche L, Le-Nguyen D, Castro B
Centre CNRS-INSERM de Pharmacologie-Endocrinologie, Montpellier, France.
Biochemistry. 1989 Mar 21;28(6):2392-8. doi: 10.1021/bi00432a009.
The solution conformation of synthetic Ecballium elaterium trypsin inhibitor II, a 28-residue peptide with 3 disulfide bridges, has been studied by 1H 2D NMR measurements. Secondary structure elements were determined: a miniantiparallel beta-sheet Met 7-Cys 9 and Gly 25-Cys 27, a beta-hairpin 20-28 with beta-turn 22-25, and two tight turns Asp 12-Cys 15 and Leu 16-Cys 19. A set of interproton distance restraints deduced from two-dimensional nuclear Overhauser enhancement spectra and 13 phi backbone torsion angles restraints were used as the basis of three-dimensional structure computations including disulfide bridges arrangement by using distance geometry calculations. Computations for the 15 possible S-S linkage combinations lead to the proposal of the array 2-19, 9-21, 15-27 as the most probable structure for EETI II.
通过¹H二维核磁共振测量研究了合成的喷瓜胰蛋白酶抑制剂II（一种具有3个二硫键的28个残基的肽）的溶液构象。确定了二级结构元件：一个小的反平行β折叠，即Met 7-Cys 9和Gly 25-Cys 27；一个具有β转角22-25的β发夹结构20-28；以及两个紧密转角Asp 12-Cys 15和Leu 16-Cys 19。从二维核Overhauser增强谱推导得到的一组质子间距离限制和¹³ϕ主链扭转角限制，被用作三维结构计算的基础，包括通过距离几何计算确定二硫键的排列。对15种可能的S-S连接组合进行计算，得出2-19、9-21、15-27这种排列是EETI II最可能的结构。
