...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Lipid Research >Purification, characterization, and cDNA sequencing of cytosolic phospholipase A(2) from equine neutrophils.
【24h】

Purification, characterization, and cDNA sequencing of cytosolic phospholipase A(2) from equine neutrophils.

机译：纯化，表征和cDNA测序的马中性粒细胞的胞质磷脂酶A（2）。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

It has been demonstrated that equine neutrophils, but not eosinophils, require exogenous arachidonic acid for calcium ionophore A23187-induced leukotriene synthesis. Because cytosolic phospholipase A(2) (cPLA(2)) plays an essential role in leukotriene formation in leukocytes, we investigated the presence of a functional cPLA(2) in equine neutrophils. To determine whether cPLA(2) from neutrophils was catalytically active, we purified the enzyme >6,500 fold with 3% recovery from equine neutrophils. The full-length cDNA sequence encoded a 749-amino acid protein. The deduced amino acid sequence demonstrated 95% identity with human and mouse cPLA(2), as well as 83 and 73% identity with chicken and zebra fish cPLA(2) protein, respectively. The equine cPLA(2) possessed some properties that distinguished the equine enzyme from the human enzyme. First, the enzyme activity of the equine cPLA(2) was differently influenced by cations as compared with the human cPLA(2). Second, the equine neutrophil cPLA(2) migrated as an approximately 105-kDa protein, in comparison with human cPLA(2) which migrated as a 110-kDa protein. A difference between equine neutrophils and eosinophils in the degree of phosphorylation of the cPLA(2) protein was observed. Thus, the cPLA(2) protein from eosinophils was constitutively phosphorylated, while the cPLA(2) protein from neutrophils was unphosphorylated.In summary, these results demonstrate that equine neutrophils indeed express an active cPLA(2) protein but that there is a difference in the degree of phosphorylation of the cPLA(2) protein between equine neutrophils and eosinophils. This difference might explain the difference between the two cell types in the capacity to produce leukotrienes from endogenous substrate.
机译：已经证明马中性粒细胞而不是嗜酸性粒细胞需要外源花生四烯酸用于钙离子载体A23187诱导的白三烯合成。由于胞质磷脂酶A（2）（cPLA（2））在白细胞中白三烯形成中起重要作用，我们调查了马中性粒细胞中功能性cPLA（2）的存在。为了确定中性粒细胞的cPLA（2）是否具有催化活性，我们从马中性粒细胞中纯化了6500倍的酶，回收率为3％。全长cDNA序列编码749个氨基酸的蛋白质。推导的氨基酸序列分别与人和小鼠cPLA（2）表现出95％的同一性，以及与鸡和斑马鱼cPLA（2）蛋白分别表现出的83％和73％的同一性。马cPLA（2）具有将马酶与人类酶区分开的某些特性。首先，与人类cPLA（2）相比，马cPLA（2）的酶活性受阳离子的影响不同。第二，马中性粒细胞cPLA（2）迁移为约105 kDa的蛋白质，而人类cPLA（2）迁移为110-kDa的蛋白质。观察到马嗜中性粒细胞和嗜酸性粒细胞在cPLA（2）蛋白磷酸化程度上的差异。因此，嗜酸性粒细胞的cPLA（2）蛋白被组成性磷酸化，而嗜中性粒细胞的cPLA（2）蛋白未被磷酸化。总而言之，这些结果表明马嗜中性粒细胞确实表达了活性cPLA（2）蛋白，但存在差异马嗜中性粒细胞和嗜酸性粒细胞之间的cPLA（2）蛋白的磷酸化程度。这种差异可能解释了两种细胞类型之间从内源性底物产生白三烯的能力方面的差异。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号