Le-Nguyen D, Heitz A, Chiche L, el Hajji M, Castro B
CCIPE, Montpellier, France.
Protein Sci. 1993 Feb;2(2):165-74. doi: 10.1002/pro.5560020205.
The three disulfide Ecballium elaterium trypsin inhibitor II (EETI II) reduction with dithiothreitol (DTT) and reoxidation of the fully reduced derivative have been examined. A common stable intermediate has been observed for both processes. Isolation and sequencing of carboxymethylated material showed that the intermediate lacks the [2-19] bridge. The NMR study showed a very strong structural conservation as compared to the native EETI II, suggesting that the bridges are the [9-21] and [15-27] native ones. The differences occurred in sections 2-7 (containing the free cysteine 2 and the Arg 4-Ile 5 active site) and 19-21 (containing the second free cysteine). Distance geometry calculations and restrained molecular dynamics refinements were also in favor of a [9-21, 15-27] arrangement and resulted in a well-conserved (7-28) segment.
用二硫苏糖醇(DTT)对三种二硫键的喷瓜胰蛋白酶抑制剂II(EETI II)进行还原,并对完全还原的衍生物进行再氧化,已对其进行了研究。在这两个过程中均观察到一种常见的稳定中间体。羧甲基化物质的分离和测序表明,该中间体缺乏[2-19]桥。核磁共振研究表明,与天然EETI II相比,其结构具有很强的保守性,这表明这些桥是天然的[9-21]和[15-27]桥。差异出现在第2-7节(包含游离半胱氨酸2和Arg 4-Ile 5活性位点)和第19-21节(包含第二个游离半胱氨酸)。距离几何计算和受限分子动力学优化也支持[9-21, 15-27]的排列,并产生了一个保守性良好的(7-28)片段。