Staphylococcus aureus sortase A exists as a dimeric protein in vitro
Staphylococcus aureus sortase A exists as a dimeric protein in vitro
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DOI：
10.1021/bi700519w
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发表时间：
2007-08-14
期刊：
影响因子：
2.9
通讯作者：
Zhang, Zhiwen
中科院分区：
文献类型：
--
作者：
Lu, Changsheng;Zhu, Jie;Zhang, Zhiwen
我们报告的金黄色葡萄球菌分选酶A（SrtA）转肽酶的自缔合行为的第一个直接观察。通过聚丙烯酰胺凝胶电泳和快速蛋白质液相色谱（FPLC）在天然条件下观察到SrtA二聚体的形成。随后的肽质量指纹和蛋白质测序实验证实了SrtA蛋白的二聚体形式。此外，SrtA可以在体外和大肠杆菌中选择性交联。对多个酶样品进行分析沉降平衡超离心，以获得约55 μ M的二聚体形成的表观K-d。最后，酶动力学研究表明SrtA的二聚体形式比单体酶更有活性。SrtA二聚体的发现可能对理解微生物生理学和开发新抗生素具有重要意义。
We report the first direct observation of the self-association behavior of the Staphylococcus aureus sortase A (SrtA) transpeptidase. Formation of a SrtA dimer was observed under native conditions by polyacrylamide gel electrophoresis and fast protein liquid chromatography (FPLC). Subsequent peptide mass fingerprinting and protein sequencing experiments confirmed the dimeric form of the SrtA protein. Furthermore, SrtA can be selectively cross-linked both in vitro and in Escherichia coli. Multiple samples of enzyme were subjected to analytical sedimentation equilibrium ultracentrifugation to obtain an apparent K-d for dimer formation of about 55,mu M. Finally, enzyme kinetic studies suggested that the dimeric form of SrtA is more active than the monomeric enzyme. Discovery of SrtA dimerization may have significant implications for understanding microbial physiology and developing new antibiotics.