Role of Charcot-Leyden Crystal Protein in Eosinophils

描述（由申请人提供）：Charcot-Leyden晶体（CLC）蛋白， 形成独特的双锥体晶体，被视为嗜酸性粒细胞的标志 参与炎症反应，最初被确定为 嗜酸性粒细胞溶血磷脂酶（LPL酶）。然而，我们已经表明，CLC不是 嗜酸性粒细胞LPL酶，更确切地说，它属于动物半乳糖凝集素超家族 基于氨基酸序列的凝集素，3D蛋白质结构，缺乏LPL酶 活性，以及其他人所显示的基因结构;它现在被指定为 半乳糖凝集素-10。我们的X-射线晶体结构显示CLC蛋白几乎是 与人半乳糖凝集素-1、-2、-3和-7相同，并具有碳水化合物 识别结构域（CRD）能够结合甘露糖，但不是标准的 通常由半乳糖凝集素识别的β-半乳糖苷糖。我们最近发现， 嗜酸性粒细胞之一s LPL酶与75 KD胰腺LPL酶相同，并且 CLC与这种LPL酶和另外两种蛋白质相互作用， 被抗LPL酶抗体识别。基于这一发现，以及我们的前任 报道用编码CLC蛋白的cDNA转染的COS细胞表现出 更高的LPL酶活性比对照细胞，我们建议测试的假设 CLC蛋白与LPL酶相互作用并激活或稳定LPL酶， 人嗜酸性粒细胞的活性。具体而言，我们建议：（1）定义 CLC蛋白的结构-功能关系？糖结合 活性，（2）鉴定CLC蛋白的生物学相关配体- 75 KD“胰腺”LPL酶和其他;（3）表征 CLC蛋白与75 KD LPL酶和其它配体的相互作用，和（4） 研究CLC蛋白和LPL酶的功能性细胞内相互作用 关于体内。

DESCRIPTION (provided by applicant):Charcot-Leyden Crystal (CLC)protein, which forms the distinctive bipyramidal crystals seen as a hallmark of eosinophil participation in inflammatory reactions, was originally identified as eosinophil lysophospholipase (LPLase). However, we have shown that CLC is not eosinophil LPLase, rather, it belongs to the galectin super family of animal lectins based on amino acid sequence, 3D protein structure, lack of LPLase activity, and as shown by others, gene structure; it is now designated as galectin-10. Our X-ray crystal structure showed CLC protein to be nearly identical to human galectin- 1, -2, -3 and -7, and to possess a carbohydrate recognition domain (CRD) capable of binding mannose, but not standard Beta-galactoside sugars generally recognized by galectins. We recently showed that one of the eosinophil?s LPLases is identical to the 75KD pancreatic LPLase, and CLC interacts with this LPLase and two other proteins that can also be recognized by anti-LPLase antibodies. Based on this finding, and our prior report that COS cells transfected with the cDNA encoding CLC protein exhibited higher LPLase activity than control cells, we propose to test the hypothesis that CLC protein interacts with LPLases and activates or stabilizes LPLase activity in human eosinophils. Specifically, we propose: (1) to define structure-function relationships for CLC protein?s carbohydrate-binding activities, (2) to identify biologically relevant ligands for CLC protein - the 75KD "pancreatic" LPLase and others, (3) to characterize the mechanisms of interaction of CLC protein with the 75 KD LPLase and other ligand(s), and (4) to study the functional intracellular interactions of CLC protein and LPLase(s about in vivo.