Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary; MTA-DE Cell Biology and Signaling Research Group, H-4032 Debrecen, Hungary.
Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
Bioorg Med Chem. 2018 May 1;26(8):1875-1884. doi: 10.1016/j.bmc.2018.02.039. Epub 2018 Feb 22.
Aralkyl and aryl selenoglycosides as well as glycosyl selenocarboxylate derivatives were assayed on the activity of protein phosphatase-1 (PP1) and -2A (PP2A) catalytic subunits (PP1c and PP2Ac) in search of compounds for PP1c and PP2Ac effectors. The majority of tested selenoglycosides activated both PP1c and PP2Ac by ∼2-4-fold in a phosphatase assay with phosphorylated myosin light chain substrate when the hydroxyl groups of the glycosyl moiety were acetylated, but they were without any effects in the non-acetylated forms. A peptide from the myosin phosphatase target subunit-1 (MYPT1) that included an RVxF PP1c-binding motif attenuated activation of PP1c by 2-Trifluoromethylbenzyl 2,3,4,6-tetra-O-acetyl-1-seleno-β-d-glucopyranoside (TFM-BASG) and 4-Bromobenzyl 2,3,4,6-tetra-O-acetyl-1-seleno-β-d-glucopyranoside (Br-BASG). MYPT1 stimulated PP2Ac and contributed to PP2Ac activation exerted by either Br-BASG or TFM-BASG. Br-BASG and TFM-BASG suppressed partially binding of PP1c to MYPT1 in surface plasmon resonance based binding experiments. Molecular docking predicted that the hydrophobic binding surfaces in PP1c for interaction with either the RVxF residues of PP1c-interactors or selenoglycosides are partially overlapped. Br-BASG and TFM-BASG caused a moderate increase in the phosphatase activity of HeLa cells in 1 h, and suppressed cell viability in 24 h incubations. In conclusion, our present study identified selenoglycosides as novel activators of PP1 and PP2A as well as provided insights into the structural background of their interactions establishing a molecular model for future design of more efficient phosphatase activator molecules.
芳基硒糖苷和芳基硒羧酸酯糖苷衍生物被检测对蛋白磷酸酶-1（PP1）和 -2A（PP2A）催化亚基（PP1c 和 PP2Ac）的活性，以寻找 PP1c 和 PP2Ac 效应物的化合物。在磷酸酶测定中，用磷酸化肌球蛋白轻链底物时，当糖苷部分的羟基乙酰化时，大多数测试的硒糖苷都使 PP1c 和 PP2Ac 活性增加约 2-4 倍，但在非乙酰化形式时没有任何作用。来自肌球蛋白磷酸酶靶蛋白-1（MYPT1）的肽，包括一个 RVxF PP1c 结合基序，减弱了 2-三氟甲基苄基 2,3,4,6-四-O-乙酰基-1-硒代-β-d-吡喃葡萄糖苷（TFM-BASG）和 4-溴苄基 2,3,4,6-四-O-乙酰基-1-硒代-β-d-吡喃葡萄糖苷（Br-BASG）对 PP1c 的激活作用。MYPT1 刺激 PP2Ac 并有助于 Br-BASG 或 TFM-BASG 发挥的 PP2Ac 激活作用。Br-BASG 和 TFM-BASG 部分抑制了 PP1c 在表面等离子体共振基础结合实验中与 MYPT1 的结合。分子对接预测，PP1c 与 PP1c 相互作用蛋白的 RVxF 残基或硒糖苷相互作用的疏水结合表面部分重叠。Br-BASG 和 TFM-BASG 在 1 小时内使 HeLa 细胞的磷酸酶活性适度增加，并在 24 小时孵育中抑制细胞活力。总之，本研究鉴定了硒糖苷作为 PP1 和 PP2A 的新型激活剂，并提供了它们相互作用的结构背景的见解，为未来设计更有效的磷酸酶激活分子建立了分子模型。
