Department of Structural Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
FEBS Lett. 2012 Nov 30;586(23):4119-25. doi: 10.1016/j.febslet.2012.10.003. Epub 2012 Oct 12.
Quiescin Sulfhydryl Oxidase (QSOX), a catalyst of disulfide bond formation, is found in both plants and animals. Mammalian, avian, and trypanosomal QSOX enzymes have been studied in detail, but plant QSOX has yet to be characterized. Differences between plant and animal QSOXs in domain composition and active-site sequences raise the question of whether these QSOXs function by the same mechanism. We demonstrate that Arabidopsis thaliana QSOX produced in bacteria is folded and functional as a sulfhydryl oxidase but does not exhibit the interdomain electron transfer observed for its animal counterpart. Based on this finding, further exploration into the respective roles of the redox-active sites in plant QSOX and the reason for their concatenation is warranted.
QSOX（含巯基二硫键异构酶）是一种二硫键形成的催化剂，存在于植物和动物中。哺乳动物、鸟类和锥虫 QSOX 酶已被详细研究，但植物 QSOX 尚未被描述。植物和动物 QSOX 在结构域组成和活性位点序列上的差异提出了一个问题，即这些 QSOX 是否通过相同的机制发挥作用。我们证明在细菌中产生的拟南芥 QSOX 折叠并作为巯基氧化酶起作用，但没有表现出与其动物对应物观察到的结构域间电子转移。基于这一发现，有必要进一步探索植物 QSOX 中氧化还原活性位点的各自作用及其连接的原因。
