Lee Changhan, Lee Junghoon, Lee Ju-young, Park Chankyu
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141, Korea.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141, Korea
FEMS Microbiol Lett. 2016 Feb;363(3). doi: 10.1093/femsle/fnv239. Epub 2015 Dec 16.
The DJ-1 superfamily is a group of proteins that shares a similarity with the human DJ-1, known to be associated with Parkinson disease. Novel glyoxalase activity, converting α-oxoaldehydes to carboxylic acids, has been reported for DJ-1 homologs in humans, worms, plants and bacteria. The four Escherichia coli genes, hchA, yajL, yhbO and elbB, have been known to share sequence similarities and catalytic residues with other DJ-1 superfamily members. We investigated here whether they exhibit similar glyoxalase activity, as previously shown for HchA protein. Purified YajL, YhbO and ElbB exhibited glyoxalase activity with different substrate specificities, optimal pHs and metal effects. Overexpressions of the homologs enhance cellular protection from exogenously added glyoxals and reduce the glyoxal-dependent increase in intracellular advanced glycation end products. Based on their expression, primarily during the stationary phase, we speculate that their roles in cells as glyoxalases are manifested during the stationary phase.
DJ-1超家族是一组与人类DJ-1具有相似性的蛋白质，已知其与帕金森病有关。据报道，人类、蠕虫、植物和细菌中的DJ-1同源物具有将α-氧代醛转化为羧酸的新型乙二醛酶活性。已知大肠杆菌的四个基因hchA、yajL、yhbO和elbB与其他DJ-1超家族成员具有序列相似性和催化残基。我们在此研究它们是否表现出与之前HchA蛋白所显示的类似乙二醛酶活性。纯化后的YajL、YhbO和ElbB表现出具有不同底物特异性、最佳pH值和金属效应的乙二醛酶活性。这些同源物的过表达增强了细胞对外源添加乙二醛的保护作用，并减少了乙二醛依赖性细胞内晚期糖基化终产物的增加。基于它们主要在稳定期表达，我们推测它们作为乙二醛酶在细胞中的作用在稳定期表现出来。
