Institut de Biotecnologia i de Biomedicina i Departament de Química, Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain.
Phys Chem Chem Phys. 2011 Jan 14;13(2):530-9. doi: 10.1039/c0cp01062f. Epub 2010 Nov 5.
We present here a theoretical study of the phosphoryl transfer catalytic mechanism of protein kinase A, which is the best known member of the large protein kinase family. We have built different theoretical models of the complete PKA-Mg(2)-ATP-substrate system to explore the two most accepted reaction pathways, using for the first time in a reaction mechanism theoretical study, the heptapeptide substrate Kemptide, which is relevant for its high efficiency and small size. The effect of the protein configuration, as modeled by two different X-ray structures with different phosphorylation states and degrees of flexibility, has been analyzed. The results indicate that the environmental conditions can influence the availability of the pathways and thus the choice of the mechanism to be followed. In addition, the roles of the two active site conserved residues, Asp166 and Lys168, have been analyzed for each reaction mechanism.
我们在这里提出了一个蛋白激酶 A（PKA）磷酸转移催化机制的理论研究，PKA 是大型蛋白激酶家族中最知名的成员。我们构建了不同的完整 PKA-Mg（2）-ATP-底物系统理论模型，以探索两种最被接受的反应途径，这是首次在反应机制理论研究中使用七肽底物 Kemptide，其具有高效和小尺寸的特点。分析了蛋白构象的影响，通过两种不同的 X 射线结构建模，这些结构具有不同的磷酸化状态和不同的柔韧性。结果表明，环境条件会影响途径的可用性，从而影响所遵循机制的选择。此外，还分析了两个活性位点保守残基 Asp166 和 Lys168 在每种反应机制中的作用。
