Heal J R, Bino S, Ray K P, Christie G, Miller A D, Raynes J G
Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College of Science Technology and Medicine, South Kensington, London, UK.
Mol Immunol. 1999 Dec;36(17):1141-8. doi: 10.1016/s0161-5890(99)00129-7.
In previous research, we were able to demonstrate that a seven amino acid residue peptide (VITFFSL), designed as an antisense peptide of the beta-bulge trigger loop region of interleukin 1beta (IL-1beta) (QGEESND; residues 48-54 [mature protein sequence]), was able to interact with IL-1 specifically and inhibit the response to IL-1 in an in vitro bioassay. The evidence was consistent with a specific interaction ocurring between antisense peptide and the trigger loop region. On the basis that antisense peptides are able to interact with their corresponding sense peptide sequences as a result of their mutually complementary hydropathic profiles (Fassina G., Verdoliva, A., Cassani, G., Melli, M., 1994. Binding of type I IL-1 receptor fragment 151-162 to IL-1. Growth Factors 10, 99-106; Maier, C.C., Moseley, H.N.B., Zhou, S., Whitaker, J.N., Blalock, J.E., 1994. Indentification of interactive determinants on idiotypic-anti-idiotypic antibodies through comparison of their hydropathic profiles. Immunomethods 5, 107-113), we devised a computer program (FINDH) to search the amino acid residue sequence of interleukin-1 type 1 receptor (IL-1 R1) for peptide motifs possessing hydropathic complementarity to the trigger loop sequence. The most complementary "best-fit peptide" motif (LITVLNI) was located in the third extracellular domain of IL-1 R1. A best-fit peptide corresponding to this motif was synthesised and found to bind to IL-1beta as well as inhibit the response to IL-1 in two independent in vitro bioassays (monitoring IL-1 dependent serum amyloid A synthesis and IL-1 dependent alkaline phosphatase activity, respectively). A second peptide motif (VIEFITL) was identified and the corresponding peptide synthesised along with a reordered version (LTILINV) of the best fit peptide. Both failed to bind measurably with IL-1beta or inhibit the response to IL-1 in the two bioassays. This best fit peptide behaved very similarly, in terms of IL-1 binding and inhibition behaviour, to the original trigger loop antisense peptide. Reference to the recently released X-ray crystal structure of IL-1beta and the IL1-R1 extracellular domain shows that the best fit peptide motif in IL-1 R1 is not apparantly interacting with the IL-1 trigger loop, although both are close in space. The intriguing possibility exists that the best fit peptide motif could represent an alternative site for IL-1beta receptor interaction which has not thus far been identified.
在先前的研究中，我们能够证明，一种设计为白细胞介素1β（IL-1β）β-凸起触发环区域（QGEESND；残基48 - 54 [成熟蛋白序列]）反义肽的七氨基酸残基肽（VITFFSL），能够在体外生物测定中与IL-1特异性相互作用并抑制对IL-1的反应。证据表明反义肽与触发环区域之间存在特异性相互作用。基于反义肽因其相互互补的亲水性轮廓能够与其相应的正义肽序列相互作用（Fassina G.，Verdoliva，A.，Cassani，G.，Melli，M.，1994。I型IL-1受体片段151 - 162与IL-1的结合。生长因子10，99 - 106；Maier，C.C.，Moseley，H.N.B.，Zhou，S.，Whitaker，J.N.，Blalock，J.E.，1994。通过比较其亲水性轮廓鉴定独特型 - 抗独特型抗体上的相互作用决定簇。免疫方法5，107 - 113），我们设计了一个计算机程序（FINDH），以在白细胞介素 - 1 型 1 受体（IL-1 R1）的氨基酸残基序列中搜索与触发环序列具有亲水性互补性的肽基序。最互补的“最佳拟合肽”基序（LITVLNI）位于IL-1 R1的第三个细胞外结构域中。合成了与该基序对应的最佳拟合肽，并发现其在两项独立的体外生物测定中（分别监测IL-1依赖性血清淀粉样蛋白A合成和IL-1依赖性碱性磷酸酶活性）与IL-1β结合并抑制对IL-1的反应。鉴定出第二个肽基序（VIEFITL），并合成了相应的肽以及最佳拟合肽的重新排序版本（LTILINV）。两者在两项生物测定中均未与IL-1β发生可测量的结合或抑制对IL-1的反应。就IL-1结合和抑制行为而言，这种最佳拟合肽的行为与原始触发环反义肽非常相似。参考最近发布的IL-1β和IL1-R1细胞外结构域的X射线晶体结构表明，IL-1 R1中的最佳拟合肽基序虽然在空间上接近，但显然并未与IL-1触发环相互作用。存在一种有趣的可能性，即最佳拟合肽基序可能代表一个尚未被识别的IL-1β受体相互作用的替代位点。
