• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Structural and Functional Analysis of the S-layer Protein Crystallisation Domain of Lactobacillus acidophilus ATCC 4356: Evidence for Protein-Protein Interaction of two Subdomains.
【24h】

Structural and Functional Analysis of the S-layer Protein Crystallisation Domain of Lactobacillus acidophilus ATCC 4356: Evidence for Protein-Protein Interaction of two Subdomains.

机译：嗜酸乳杆菌ATCC 4356的S层蛋白质结晶域的结构和功能分析：两个子域的蛋白质与蛋白质相互作用的证据。

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 of the crystallisation domain, SAN, of the S(A)-protein of Lactobacillus acidophilus ATCC 4356 was analysed by insertion and deletion mutagenesis, and by proteolytic treatment. Mutant S(A)-protein synthesised in Escherichia coli with 7-13 amino acid insertions near the N terminus or within regions of sequence variation in SAN (amino acid position 7, 45, 114, 125, 193), or in the cell wall-binding domain (position 345) could form crystalline sheets, whereas insertions in conserved regions or in regions with predicted secondary structure elements (positions 30, 67, 88 and 156) destroyed this capacity. FACscan analysis of L.acidophilus synthesising three crystallising and one non-crystallising S(A)-protein c-myc (19 amino acid residues) insertion mutant was performed with c-myc antibodies. Fluorescence was most pronounced for insertions at positions 125 and 156, less for position 45 and severely reduced for position 7. By cytometric flow sorting a transformant harbouring the mutant S(A)-protein gene (position 125) was isolated that showed an increased fluorescense signal. Immunofluorescence microscopy suggested that the transformant synthesized mutant S(A)-protein only. PCR analysis of the transformant grown in the absence of selection pressure indicated that the mutant allele was stably integrated in the chromosome. Proteolytic treatment of S(A)-protein indicated that only sites near the middle of SAN are susceptible, although potential cleavage sites are present through the entire molecule. Expression in E.coli of DNA sequences encoding the two halves of SAN yielded peptides that could oligomerize. Our results indicate that SAN consists of a approximately 12kDa N and a approximately 18kDa C-terminal subdomain linked by a surface exposed loop. The capacity of S(A)-protein of L.acidophilus to present epitopes, up to approximately 19 amino acid residues in length, at the bacterial surface in a genetically stable form, makes the system, in principle, suitable for application as an oral delivery vehicle.
机译：通过插入和缺失诱变以及蛋白水解处理分析了嗜酸乳杆菌ATCC 4356的S（A）蛋白的结晶结构域SAN的结构。在大肠杆菌中合成的突变S（A）蛋白，在N末端附近或SAN的序列变异区域内（氨基酸位置7、45、114、125、193）或细胞壁中插入了7-13个氨基酸结合域（位置345）可能形成结晶片，而在保守区域或具有预测二级结构元素的区域（位置30、67、88和156）中插入会破坏该能力。用c-myc抗体进行嗜酸乳杆菌的FACscan分析，合成了三个结晶的和一个非结晶的S（A）-蛋白c-myc（19个氨基酸残基）插入突变体。荧光在位置125和156插入最明显，在位置45减少，在位置7严重减少。通过流式细胞术分选出一个含有突变型S（A）-蛋白质基因（位置125）的转化子，荧光强度增加。信号。免疫荧光显微镜表明该转化子仅合成了突变体S（A）-蛋白。在没有选择压力的情况下生长的转化体的PCR分析表明，突变等位基因稳定整合在染色体中。 S（A）-蛋白的蛋白水解处理表明，仅SAN中部附近的位点易感，尽管整个分子中均存在潜在的裂解位点。在大肠杆菌中表达编码两半SAN的DNA序列产生了可以寡聚的肽。我们的结果表明，SAN由一个约12kDa的N和一个约18kDa的C末端亚结构域组成，该子域通过表面暴露的环连接。嗜酸乳杆菌的S（A）蛋白以遗传稳定形式在细菌表面呈递表位的能力，该表位的长度最多约为19个氨基酸残基，因此，该系统原则上适用于口服送货车。

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