应用进化踪迹及分子动力学模拟研究beta2肾上腺素受体突变活性

β2肾上腺素受体(β2adrenergic receptor,β2AR)是G蛋白耦联受体(G protein coupled receptors,GPCRs)超家族中的一员,也是研究治疗哮喘的关键药物受体靶标.采用进化踪迹(evolutionary trace,ET)方法分析肾上腺素受体家族跨膜区片段序列,识别出了44个保守的残基,然后将β2肾上腺素受体以及受体D130N活性突变体、D79N失活突变体进行分子动力学模拟,试图找出与受体不同功能状态相关的结构动力学特征.发现受体DRY motif中的D130远离R131而转向K149残基这一结构特征与受体活性高度关联,此外,从残基相互作用的变化推断出了受体helix 2,4 and 6伴随着受体活化而发生的运动.这些研究结果对进一步探索β2肾上腺素受体突变体的激活机制以及所诱发疾病的分子机理提供了依据.

Evolutionary Trace and Molecular Dynamics Simulation of the Beta2 Adrenergic Receptor Mutation-induced Activation

Beta2 adrenergic receptor (β2 AR) is one member of G protein coupled receptors (GPCRs), which is a key pharmaceutical target in the treatment of asthma. Evolutionary trace (ET) method was employed to analyze AR sequences and 44 conserved residues were identified. Then molecular dynamics (MD) simulation of the β2 wild-type receptor, D130N active mutant and D79N inactive mutant were carried out and tried to explore the structural/dynamic features characterizing functionally different states of the receptor,by means of investigating ET identified conserved basic residues in the wild-type receptor and its two mutants. Particularly, it was found that the departing of D130 from R131 of DRY motif and approaching to K149 are highly correlated with the receptor activation,and the movement of helix 2, 4 and 6 upon receptor activation is inferred from the observation that R151 and K270 interact with other residues in the receptor active state on the basis of little change of the side chain orientations. The results might provide further insights into the activating mechanism of β2 AR mutants, as well as the molecular bases of the diseases induced by the mutations of the receptor.