Ahn Misun, Kim Seungbum, Kang Mira, Ryu Yeonwoo, Kim T Doohun
Division of Biotechnology and Molecular Engineering, College of Engineering, Ajou University, Suwon 443-749, Republic of Korea.
Biochem Biophys Res Commun. 2006 Aug 11;346(4):1142-9. doi: 10.1016/j.bbrc.2006.05.213. Epub 2006 Jun 13.
Alpha-synuclein, a major constituent of Lewy bodies (LBs), has been implicated to play a critical role in the pathogenesis of Parkinson's disease (PD), although the physiological function of alpha-synuclein has not yet been known. Here we have shown that alpha-synuclein, which has no well-defined secondary or tertiary structure, can protect the enzyme activity of microbial esterases against stress conditions such as heat, pH, and organic solvents. In particular, the flexibility of alpha-synuclein and its C-terminal region seems to be important for complex formation, but the structural integrity of the C-terminal region may not be required for stabilization of enzyme activity. In addition, atomic force microscopy (AFM) and in vivo enzyme assays showed highly specific interactions of esterases with alpha-synuclein. Our results indicate that alpha-synuclein not only protects the enzyme activity of microbial esterases in vitro, but also can stabilize the active conformation of microbial esterases in vivo.
α-突触核蛋白是路易小体（LBs）的主要成分，尽管其生理功能尚不清楚，但已被认为在帕金森病（PD）的发病机制中起关键作用。在这里我们已经表明，没有明确二级或三级结构的α-突触核蛋白可以保护微生物酯酶的酶活性免受诸如热、pH值和有机溶剂等应激条件的影响。特别是，α-突触核蛋白及其C末端区域的灵活性似乎对复合物形成很重要，但C末端区域的结构完整性对于酶活性的稳定可能不是必需的。此外，原子力显微镜（AFM）和体内酶分析表明酯酶与α-突触核蛋白有高度特异性的相互作用。我们的结果表明，α-突触核蛋白不仅在体外保护微生物酯酶的酶活性，而且在体内也能稳定微生物酯酶的活性构象。
