Dripps D J, Brandhuber B J, Thompson R C, Eisenberg S P
Synergen, Inc., Boulder, Colorado 80301.
J Biol Chem. 1991 Jun 5;266(16):10331-6.
The interleukin-1 receptor antagonist (IL-1ra) is a protein capable of inhibiting receptor binding and biological activities of IL-1 without inducing an IL-1-like response. Equilibrium binding and kinetic experiments show that IL-1ra binds to the 80-kDa IL-1 receptor on the murine thymoma cell line EL4 with an affinity (KD = 150 pM) approximately equal to that of IL-1 alpha and IL-1 beta for this receptor. However, IL-1ra is unable to induce two early events associated with IL-1 activity. Surface-bound IL-1ra does not undergo receptor-mediated internalization, and IL-1ra does not activate the protein kinase activity responsible for down-modulation of the EGF receptor on the murine 3T3 fibroblast cell line. The failure to induce general, early responses characteristic of IL-1 indicates that IL-1ra is unlikely to act as an agonist on any cell expressing the 80-kDa receptor.
白细胞介素-1受体拮抗剂（IL-1ra）是一种蛋白质，能够抑制IL-1的受体结合及生物学活性，而不诱导类似IL-1的反应。平衡结合和动力学实验表明，IL-1ra与鼠胸腺瘤细胞系EL4上的80 kDa IL-1受体结合，其亲和力（KD = 150 pM）与IL-1α和IL-1β对该受体的亲和力大致相当。然而，IL-1ra无法诱导与IL-1活性相关的两个早期事件。表面结合的IL-1ra不会发生受体介导的内化，并且IL-1ra不会激活负责下调鼠3T3成纤维细胞系上表皮生长因子受体的蛋白激酶活性。无法诱导IL-1的一般早期反应表明，IL-1ra不太可能在任何表达80 kDa受体的细胞上作为激动剂发挥作用。
