Department of Molecular Therapeutics, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA.
Structure. 2013 Nov 5;21(11):1942-53. doi: 10.1016/j.str.2013.08.023. Epub 2013 Sep 26.
AMP-activated protein kinase (AMPK) monitors cellular energy, regulates genes involved in ATP synthesis and consumption, and is allosterically activated by nucleotides and synthetic ligands. Analysis of the intact enzyme with hydrogen/deuterium exchange mass spectrometry reveals conformational perturbations of AMPK in response to binding of nucleotides, cyclodextrin, and a synthetic small molecule activator, A769662. Results from this analysis clearly show that binding of AMP leads to conformational changes primarily in the γ subunit of AMPK and subtle changes in the α and β subunits. In contrast, A769662 causes profound conformational changes in the glycogen binding module of the β subunit and in the kinase domain of the α subunit, suggesting that the molecular binding site of the latter resides between the α and β subunits. The distinct short- and long-range perturbations induced upon binding of AMP and A769662 suggest fundamentally different molecular mechanisms for activation of AMPK by these two ligands.
腺苷酸活化蛋白激酶（AMPK）监测细胞能量，调节涉及 ATP 合成和消耗的基因，并通过核苷酸和合成配体变构激活。用氢/氘交换质谱法分析完整的酶，揭示了核苷酸、环糊精和合成小分子激活剂 A769662 结合时 AMPK 的构象扰动。该分析的结果清楚地表明，AMP 的结合主要导致 AMPK 的γ亚基的构象变化，并导致α和β亚基的细微变化。相比之下，A769662 导致β亚基的糖原结合模块和α亚基的激酶结构域发生深刻的构象变化，这表明后者的分子结合位点位于α和β亚基之间。AMP 和 A769662 结合后诱导的明显的短程和长程扰动表明，这两种配体激活 AMPK 的分子机制截然不同。
