Solution structure and dynamics of a serpin reactive site loop using interleukin 1β as a presentation scaffold
Solution structure and dynamics of a serpin reactive site loop using interleukin 1β as a presentation scaffold
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DOI：
10.1093/protein/12.3.189
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发表时间：
1999-03-01
期刊：
影响因子：
--
通讯作者：
Wolfson, AJ
中科院分区：
文献类型：
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作者：
Arico-Muendel, CC;Patera, A;Wolfson, AJ
利用人白细胞介素-1 β (il -1 β)作为表征白细胞弹性酶生理抑制剂serpin α - 1-antitrypsin （A1AT）活性位点环（RSL）的展示支架，用A1AT的10个残基P5-P5序列EAIPMSIPPE替换IL1 β的50-53个残基（对应于IL1 β暴露的反转），生成了一个嵌合蛋白。嵌合体（抗胰蛋白酶-白细胞介素，AT-IL）特异性抑制弹性酶，也结合il - 1 β受体，AT-IL的多核磁共振表征证实，除了插入的序列外，嵌合体中il - 1 β支架的结构被保留。对插入的RSL的结构与分离的10残基RSL肽的结构进行了分析，结果表明RSL肽在溶液中基本上是无序的。与il - 1 β支架相比，嵌合RSL也被发现是溶剂暴露的，构象移动，并且没有证据表明在N和c端连接之外与支架持续相互作用。然而，相对于分离的RSL， AT-IL在化学位移和NOE模式上表现出显著差异，这与非随机结构的局部特征相一致。这些特征与P1-P1'残基的接近表明它们可能是嵌合体抑制活性的原因。
Human interleukin-1 beta (IL1 beta) was used as a presentation scaffold for the characterization of the reactive site loop (RSL) of the serpin alpha 1-antitrypsin (A1AT), the physiological inhibitor of leukocyte elastase, A chimeric protein was generated by replacement of residues 50-53 of IL1 beta, corresponding to an exposed reverse turn in IL1 beta, with the 10-residue P5-P5' sequence EAIPMSIPPE from A1AT. The chimera (antitrypsin-interleukin, AT-IL) inhibits elastase specifically and also binds the IL1 beta receptor, Multinuclear NMR characterization of AT-IL established that, with the exception of the inserted sequence, the structure of the IL1 beta scaffold is preserved in the chimera. The structure of the inserted RSL was analyzed relative to that of the isolated 10-residue RSL peptide, which was shown to be essentially disordered in solution. The chimeric RSL was also found to be solvent exposed and conformationally mobile in comparison with the IL1 beta scaffold, and there was no evidence of persisting interactions with the scaffold outside of the N- and C-terminal linkages. However, AT-IL exhibits significant differences in chemical shift and NOE patterns relative to the isolated RSL that are consistent with local features of non-random structure. The proximity of these features to the P1-P1' residues suggests that they may be responsible for the inhibitory activity of the chimera.