Shuck M E, Eessalu T E, Tracey D E, Bienkowski M J
Department of Cell Biology, Upjohn Company, Kalamazoo, MI 49007.
Eur J Immunol. 1991 Nov;21(11):2775-80. doi: 10.1002/eji.1830211119.
A cDNA coding for the human interleukin 1 receptor antagonist protein (IL 1Ra) was used to clone the corresponding murine cDNA. The nucleotide sequence of the open reading frame coding for the processed form of mIL 1Ra predicted a 152-residue protein that was 77% identical to human IL 1Ra. The cellular and tissue distribution of murine IL 1Ra (mIL 1Ra) transcripts showed high levels in macrophages and skin while lower levels were detected in tissues that contain significant numbers of resident macrophages. The portion of the mIL 1Ra cDNA that codes for the mature form of the protein was placed under the control of a Trp promoter and expressed in E. coli at a level of 37% of total cell protein. The expressed protein was secreted into the periplasm and was purified to homogeneity in a single step by cation-exchange chromatography. Recombinant mIL 1Ra competitively inhibited 125I-labeled IL 1 alpha binding to murine type I IL 1R present on EL4 6.1 cells (Ki value of 0.21 nM) and antagonized IL 1-stimulated co-mitogenesis in murine thymocytes (0.7 x 10(6)-1.1 x 10(6) units/mg).
使用编码人白细胞介素1受体拮抗剂蛋白（IL-1Ra）的cDNA克隆相应的鼠cDNA。编码加工形式的mIL-1Ra的开放阅读框的核苷酸序列预测了一种152个残基的蛋白质，其与人IL-1Ra的同源性为77%。鼠IL-1Ra（mIL-1Ra）转录本的细胞和组织分布显示，巨噬细胞和皮肤中的水平较高，而在含有大量常驻巨噬细胞的组织中检测到的水平较低。编码该蛋白质成熟形式的mIL-1Ra cDNA部分置于色氨酸启动子的控制下，并在大肠杆菌中表达，表达水平占总细胞蛋白的37%。表达的蛋白质分泌到周质中，并通过阳离子交换色谱一步纯化至同质。重组mIL-1Ra竞争性抑制125I标记的IL-1α与EL4 6.1细胞上存在的鼠I型IL-1R结合（Ki值为0.21 nM），并拮抗IL-1刺激的鼠胸腺细胞共增殖（0.7×10^6 - 1.1×10^6单位/毫克）。
