Department of Molecular Biotechnology and Kumho Life Science Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 500-757, Republic of Korea.
J Plant Res. 2015 Jan;128(1):201-9. doi: 10.1007/s10265-014-0670-y. Epub 2014 Oct 19.
Allene oxide synthase-1 from Oryza sativa (OsAOS1) localizes to the chloroplast, but lacks a putative chloroplast targeting sequence typically found in dicot AOS. Here, kinetic parameters and the oligomerization state/subunit composition of OsAOS1 were characterized in vitro in the absence or presence of detergent micelles. The catalytic efficiency (k(cat)/K(m)) of OsAOS1 reached a maximum near the critical micelle concentration for polyoxyethylene 10 tridecyl ether. Native gel analysis showed that OsAOS1 exists as a multimer in the absence of detergent micelles. The multimeric form of OsAOS1 was stably cross-linked in the absence of detergents, while only monomeric OsAOS1 was detected in the presence of detergent micelles. Gel filtration analysis indicated that the oligomeric state of OsAOS1 depends strongly on the detergents and that the monomer becomes the predominant form in the presence of detergent micelles. These data suggest that the detergent-dependent oligomeric state of OsAOS1 is an important factor for the regulation of its catalytic efficiency.
来自水稻（Oryza sativa）的丙二烯氧化物合酶-1（OsAOS1）定位于叶绿体，但缺乏通常在双子叶 AOS 中发现的假定的叶绿体靶向序列。在这里，在不存在或存在去污剂胶束的情况下，体外表征了 OsAOS1 的动力学参数和寡聚状态/亚基组成。OsAOS1 的催化效率（kcat/Km）在聚氧乙烯 10 十三烷基醚的临界胶束浓度附近达到最大值。天然凝胶分析表明，在不存在去污剂胶束的情况下，OsAOS1 以多聚体形式存在。在不存在去污剂的情况下，OsAOS1 的多聚体形式稳定交联，而在存在去污剂胶束的情况下仅检测到单体 OsAOS1。凝胶过滤分析表明，OsAOS1 的寡聚状态强烈依赖于去污剂，并且在存在去污剂胶束的情况下，单体成为主要形式。这些数据表明，OsAOS1 的去污剂依赖性寡聚状态是调节其催化效率的重要因素。
