Identification of a Novel Eosinophil Chemotactic Cytokine (ECF-L) as a Chitinase Family Protein*
Identification of a Novel Eosinophil Chemotactic Cytokine (ECF-L) as a Chitinase Family Protein*
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DOI：
10.1074/jbc.275.2.1279
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发表时间：
2000-01
期刊：
影响因子：
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通讯作者：
M. Owhashi;H. Arita;N. Hayai
中科院分区：
文献类型：
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作者：
M. Owhashi;H. Arita;N. Hayai
通过阴离子交换色谱、Procion 红色琼脂糖亲和色谱、尺寸排阻高效液相色谱 (HPLC) 和反相 HPLC 相结合，从小鼠脾细胞培养上清液中纯化出一种新型嗜酸性粒细胞趋化细胞因子 (ECF-L)。通过直接蛋白质测序确定NH2-末端氨基酸序列。从cDNA文库中分离出1,506个核苷酸的ECF-L cDNA克隆，该核苷酸序列预测了397个氨基酸的成熟蛋白质。重组ECF-L显示出与天然ECF-L相当的嗜酸性粒细胞趋化活性水平，并且该活性被针对ECF-L的单克隆抗体抑制。 ECF-L还在体外吸引T淋巴细胞和骨髓多形核白细胞，而在体内引起嗜酸性粒细胞选择性外渗。 ECF-L mRNA 在脾、骨髓、肺和心脏中高表达。全面的 GenBank 数据库搜索表明 ECF-L 是一种几丁质酶家族蛋白。 ECF-L 保留了几丁质酶家族蛋白中高度保守的氨基酸，但水解中提供质子所必需的 Asp 和 Glu 残基分别被 Asn 和 Gln 取代。尽管 ECF-L 在 NH2 末端附近含有类似于趋化因子家族蛋白的共有 CXC 序列，但 ECF-L 的其余部分与趋化因子显示出较差的同源性。
A novel eosinophil chemotactic cytokine (ECF-L) was purified from the culture supernatant of splenocytes of mice by a combination of anion-exchange chromatography, Procion red-agarose affinity chromatography, size exclusion high performance liquid chromatography (HPLC), and reverse phase HPLC. The NH2-terminal amino acid sequence was determined by direct protein sequencing. An ECF-L cDNA clone of 1,506 nucleotides was isolated from a cDNA library, and the nucleotide sequence predicted a mature protein of 397 amino acids. A recombinant ECF-L showed a level of eosinophil chemotactic activity comparable with that of natural ECF-L, and the activity was inhibited by a monoclonal antibody to ECF-L. ECF-L also attracted T lymphocytes and bone marrow polymorphonuclear leukocytes in vitro, whereas it caused selective extravasation of eosinophils in vivo. ECF-L mRNA was highly expressed in spleen, bone marrow, lung, and heart. A comprehensive GenBank data base search revealed that ECF-L is a chitinase family protein. ECF-L retains those amino acids highly conserved among chitinase family proteins, but Asp and Glu residues essential for the proton donation in hydrolysis were replaced by Asn and Gln, respectively. Although ECF-L contains a consensus CXC sequence near the NH2 terminus akin to chemokine family proteins, the rest of ECF-L shows poor homology with chemokines.