Moser B, Dewald B, Barella L, Schumacher C, Baggiolini M, Clark-Lewis I
Theodor-Kocher Institute, University of Bern, Switzerland.
J Biol Chem. 1993 Apr 5;268(10):7125-8.
We have previously shown that the residues Glu4-Leu5-Arg6 (ELR) preceding the first cysteine at the N terminus of the 72-residue form of interleukin-8 (IL-8) are essential for receptor binding and neutrophil activation (Clark-Lewis, I., Schumacher, C., Baggiolini, M., and Moser, B. (1991) J. Biol. Chem. 266, 23128-23134). We have now synthesized a series of analogs of IL-8(4-72), the truncated form of IL-8 with the N-terminal sequence ELRC, as potential IL-8 antagonists. Among 26 analogs with deletions or amino acid replacements in the ELR region several inhibited IL-8 function. The most potent were IL-8(6-72), with Arg6 at the N terminus, and IL-8,AAR(7-72) with N-terminal Ala4-Ala5 instead of Glu4-Leu5. They inhibited IL-8 receptor binding, exocytosis (IC50 0.3 microM), as well as chemotaxis and the respiratory burst. Inhibition was restricted to responses elicited by IL-8, GRO alpha, or NAP-2, and no effect was observed when the unrelated agonists fMet-Leu-Phe or C5a were used as stimuli. These results demonstrate that selective antagonists that prevent or attenuate the action of IL-8 and its related chemotactic cytokines are obtained by modification of the ELR sequence at the N terminus.
我们先前已表明，白细胞介素-8（IL-8）72个氨基酸形式的N端第一个半胱氨酸之前的Glu4-Leu5-Arg6（ELR）残基对于受体结合和中性粒细胞激活至关重要（Clark-Lewis，I.，Schumacher，C.，Baggiolini，M.和Moser，B.（1991）J. Biol. Chem. 266，23128 - 23134）。我们现在合成了一系列IL-8(4 - 72)的类似物，即N端序列为ELRC的IL-8截短形式，作为潜在的IL-8拮抗剂。在ELR区域有缺失或氨基酸替换的26种类似物中，有几种抑制了IL-8的功能。最有效的是N端为Arg6的IL-8(6 - 72)，以及N端为Ala4-Ala5而非Glu4-Leu5的IL-8,AAR(7 - 72)。它们抑制IL-8受体结合、胞吐作用（IC50为0.3 microM）以及趋化性和呼吸爆发。抑制作用仅限于由IL-8、GROα或NAP-2引发的反应，当使用无关激动剂fMet-Leu-Phe或C5a作为刺激时未观察到影响。这些结果表明，通过修饰N端的ELR序列可获得阻止或减弱IL-8及其相关趋化细胞因子作用的选择性拮抗剂。
