...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >The sterol carrier protein-2 amino terminus: a membrane interaction domain.
【24h】

The sterol carrier protein-2 amino terminus: a membrane interaction domain.

机译：固醇载体蛋白2氨基末端：膜相互作用域。

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

Sterol carrier protein-2 (SCP2) is a small, 123 amino acid, protein postulated to play a role in intracellular transport and metabolism of lipids such as cholesterol, phospholipids, and branched chain fatty acids. While it is thought that interaction of SCP2 with membranes is necessary for lipid transfer, evidence for this possibility and identification of a membrane interaction domain within SCP2 has remained elusive. As shown herein with circular dichroism and a direct binding assay, SCP2 bound to small unilamellar vesicle (SUV) membranes to undergo significant alteration in secondary structure. The SCP2 amphipathic N-terminal 32 amino acids, comprised of two alpha-helical segments, were postulated to represent a putative phospholipid interaction site. This hypothesis was tested with a series of SCP2 N-terminal peptides, circular dichroism, and direct binding studies. The SCP2 N-terminal peptide (1-32)SCP2, primarily random coil in aqueous buffer, adopted alpha-helical structure upon interaction with membranes. The induction of alpha-helical structure in the peptide was maximal when the membranes contained a high mole percent of negatively charged phospholipid and of cholesterol. While deletion of the second alpha-helical segment within this peptide had no effect on formation of the first alpha-helix, it significantly weakened the peptide interaction with membranes. Substitution of Leu(20) with Glu(20) in the N-terminal peptide disrupted the alpha-helix structure and greatly weakened the peptide interaction with membranes. Finally, deletion of the first nine nonhelical amino acids had no effect either on formation of alpha-helix or on peptide binding to membranes. N-Terminal peptide (1-32)SCP2 competed with SCP2 for binding to SUV. These data were consistent with the N-terminus of SCP2 providing a membrane interaction domain that preferentially bound to membranes rich in anionic phospholipid and cholesterol.
机译：甾醇载体蛋白2（SCP2）是一种小的123个氨基酸，被认为在脂质如胆固醇，磷脂和支链脂肪酸的细胞内运输和代谢中起作用。尽管认为SCP2与膜的相互作用对于脂质转移是必需的，但这种可能性的证据以及SCP2中膜相互作用域的鉴定仍然难以捉摸。如本文通过圆形二向色性和直接结合测定法所示，SCP2结合到小的单层囊泡（SUV）膜上，从而在二级结构中发生重大改变。假定由两个α-螺旋区段组成的SCP2两亲性N末端32个氨基酸代表一个假定的磷脂相互作用位点。通过一系列SCP2 N末端肽，圆二色性和直接结合研究测试了该假设。 SCP2 N末端肽（1-32）SCP2主要是在水性缓冲液中的无规卷曲，在与膜相互作用时采用α螺旋结构。当膜包含高摩尔百分比的带负电荷的磷脂和胆固醇时，肽中的α-螺旋结构诱导最大。尽管该肽内的第二个α-螺旋区段的缺失对第一个α-螺旋的形成没有影响，但它显着削弱了该肽与膜的相互作用。在N末端肽中用Glu（20）取代Leu（20）破坏了α-螺旋结构并大大削弱了肽与膜的相互作用。最后，删除前九个非螺旋氨基酸对α-螺旋的形成或与膜结合的肽均无影响。 N-末端肽（1-32）SCP2与SCP2竞争与SUV的结合。这些数据与SCP2的N端一致，后者提供了一个膜相互作用域，该域优先与富含阴离子磷脂和胆固醇的膜结合。

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