Molecular analysis of Streptococcus anginosus-derived SagA peptides.
Molecular analysis of Streptococcus anginosus-derived SagA peptides.
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发表时间：
2014-08
影响因子：
2
通讯作者：
Yuki Kawaguchi;Atsushi Tabata;H. Nagamune;K. Ohkura
中科院分区：
文献类型：
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作者：
Yuki Kawaguchi;Atsushi Tabata;H. Nagamune;K. Ohkura
背景SagA1和SagA2分子产自β-溶血性链球菌。心绞痛由前导肽和前肽组成，其成熟形式具有溶血活性，与著名的链球菌多肽毒素--链球菌溶血素一样。这些SAGA分子的功能被认为依赖于分子内杂环的形成。在本研究中，我们研究了SagA1、SagA2和化脓性链球菌SagA(SPySagA)涉及杂环的分子特征，重点是它们的杂环形成。材料与方法利用分子建模技术构建SagA1、SagA2和SPySagA的分子模型。对模拟的SAGA分子进行了分子动力学和分子力学分析，得到了它们的能量分布。结果所建模型的SagA1、SagA2和SPySagA的总能量随着杂环的形成而降低，杂环形成后，前导肽和前肽之间的边界清晰可见。结论分子内杂环的形成改变了SAGA分子的柔韧性，其功能(如溶血活性)可能受杂环形成的结构转变的调节。
BACKGROUND SagA1 and SagA2 molecules produced from beta-hemolytic Streptococcus anginosus subsp. anginosus are composed of a leader peptide and a propeptide, and their mature form has hemolytic activity as a well-known Streptococcal peptide toxin, streptolysin. The function of these SagA molecules is thought to be dependent on intra-molecular heterocycle formation. In this study, we examined the heterocycle-involved molecular features of SagA1, SagA2, and S. pyogenes SagA (SPySagA), focusing on their heterocycle formation. MATERIALS AND METHODS Molecular models of SagA1, SagA2, and SPySagA were constructed using a molecular modeling technique. Molecular dynamics and molecular mechanic analyses of the modeled SagA molecules were performed to obtain their energy profiles. RESULTS Total energy of the modeled SagA1, SagA2, and SPySagA decreased with heterocycle formation, and the border between the leader peptide and propeptide was clearly observed after heterocycle formation. CONCLUSION The flexibility of SagA molecules was changed by intramolecular heterocycle formation, and their function (e.g. hemolytic activity) seems to be regulated by structural transition with heterocycle formation.