Shapiguzov Alexey, Edvardsson Anna, Vener Alexander V
Division of Cell Biology, Linköping University, SE-581 85 Linköping, Sweden.
FEBS Lett. 2006 Jun 26;580(15):3671-6. doi: 10.1016/j.febslet.2006.05.054.
Proteomic, enzymatic, and mutant analyses revealed that peptidyl-prolyl isomerase (PPIase) activity in the chloroplast thylakoid lumen of Arabidopsis is determined by two immunophilins: AtCYP20-2 and AtFKBP13. These two enzymes are responsible for PPIase activity in both soluble and membrane-associated fractions of thylakoid lumen suggesting that other lumenal immunophilins are not active towards the peptide substrates. In thiol-reducing conditions PPIase activity of the isolated AtFKBP13 and of the total thylakoid lumen is suppressed several fold. Profound redox-dependence of PPIase activity implies oxidative activation of protein folding catalysis under oxidative stress and photosynthetic oxygen production in the thylakoid lumen of plant chloroplasts.
蛋白质组学、酶学和突变体分析表明，拟南芥叶绿体类囊体腔中的肽基脯氨酰异构酶（PPIase）活性由两种亲环蛋白决定：AtCYP20-2和AtFKBP13。这两种酶负责类囊体腔可溶部分和膜相关部分中的PPIase活性，这表明其他腔内亲环蛋白对肽底物无活性。在硫醇还原条件下，分离出的AtFKBP13和整个类囊体腔的PPIase活性被抑制了几倍。PPIase活性对氧化还原的深度依赖性意味着在植物叶绿体类囊体腔的氧化应激和光合产氧过程中，蛋白质折叠催化的氧化激活。
