...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >The Structural Characteristics of Nonspecific Lipid Transfer Proteins Explain Their Resistance to Gastroduodenal Proteolysis
【24h】

The Structural Characteristics of Nonspecific Lipid Transfer Proteins Explain Their Resistance to Gastroduodenal Proteolysis

机译：非特异性脂质转移蛋白的结构特征说明其对胃十二指肠蛋白水解的抗性

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

The structure and stability of the allergenic nonspecific lipid transfer protein (LTP) of peach werencompared with the homologous LTP1 of barley and its liganded formLTP1b.All three proteins were resistantnto gastric pepsinolysis and were only slowly digested at 1 to 2 out of 14 potential tryptic and chymotrypticncleavage sites under duodenal conditions. Peach LTP was initially cleaved at Tyr79-Lys80 and then at Arg39-nThr40 (a site lost in barley LTP1). Molecular dynamics simulations of the proteins under folded conditionsnshowed that the backbone flexibility is limited, explaining the resistance to duodenal proteolysis. Arg39 andnLys80 side chains were more flexible in simulations of peach compared with barley LTP1. This may explainndifferences in the rates of cleavage observed experimentally for the two proteins and suggests that thenflexibility of individual amino acid side chains could be important in determining preferred proteolyticncleavage sites. In order to understand resistance to pepsinolysis, proteins were characterized by NMRnspectroscopy at pH 1.8. This showed that the helical regions of both proteins remain folded at this pH. NMRnhydrogen exchange studies confirmed the rigidity of the structures at acidic pH, with barley LTP1 showingnsome regions with greater protection. Collectively, these data suggest that the rigidity of the LTP scaffold isnresponsible for their resistance to proteolysis. Gastroduodenal digestion conditions do not disrupt the 3Dnstructure of peach LTP, explaining why LTPs retain their ability to bind IgE after digestion and hence theirnallergenic potential.
机译：桃的变应性非特异性脂质转移蛋白（LTP）的结构和稳定性与大麦的同源LTP1及其配体（mLTP1b）相比，这三种蛋白均对胃蛋白酶解有抵抗力，在14种潜在的胰蛋白酶和胰蛋白酶中仅在1-2处缓慢消化。十二指肠条件下的糜蛋白酶分裂位点。桃LTP最初在Tyr79-Lys80处切割，然后在Arg39-nThr40（在大麦LTP1中丢失的位点）切割。蛋白质在折叠条件下的分子动力学模拟表明，骨架的柔性受到限制，这说明了对十二指肠蛋白水解的抵抗力。与大麦LTP1相比，Arg39和nLys80侧链在桃子的模拟中更为灵活。这可能解释了通过实验观察到的两种蛋白质的切割速率之间的差异，并暗示了各个氨基酸侧链的柔性对于确定优选的蛋白水解位点可能很重要。为了了解对胃蛋白酶分解的抗性，蛋白在NMR pH值为1.8的条件下进行了表征。这表明两种蛋白质的螺旋区在此pH下均保持折叠。 NMRn氢交换研究证实了在酸性pH下结构的刚性，大麦LTP1显示出一些具有更大保护作用的区域。总体而言，这些数据表明，LTP支架的刚度对其抵抗蛋白水解作用不负责任。胃十二指肠消化条件不会破坏桃LTP的3Dn结构，这解释了为什么LTP在消化后仍保持其结合IgE的能力，并因此具有致纳力。

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