p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, 138648, Singapore.
Bioinformatics Institute, A*STAR (Agency for Science, Technology and Research), 30 Biopolis Street, #07-01 Matrix, 138671, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore; School of Biological Sciences, Nanyang Technological University, 50 Nanyang Drive, 637551, Singapore.
Biochim Biophys Acta Gen Subj. 2021 Jan;1865(1):129775. doi: 10.1016/j.bbagen.2020.129775. Epub 2020 Oct 27.
Intrinsically disordered regions (IDRs) in proteins can regulate their activity by facilitating protein-protein interactions (PPIs) as exemplified in the recruitment of the eukaryotic translation initiation factor 4E (eIF4E) protein by the protein eIF4G. Deregulation of this PPI module is central to a broad spectrum of cancer related malignancies and its targeted inhibition through bioactive peptides is a promising strategy for therapeutic intervention.
We employed molecular dynamics simulations coupled with biophysical assays to rationally develop peptide derivatives from the intrinsically disordered eIF4G scaffold by incorporating non-natural amino acids that facilitates disorder-to-order transition.
The conformational heterogeneity of these peptides and the degree of structural reorganization required to adopt the optimum mode of interaction with eIF4E underscores their differential binding affinities. The presence of a pre-structured local helical element in the ensemble of structures was instrumental in the efficient docking of the peptides on to the protein surface. The formation of Y4: P38 hydrogen-bond interaction between the peptide and eIF4E is a rate limiting event in the efficient recognition of the protein since it occurs through the disordered region of the peptide.
These insights were exploited to further design features into the peptide to propagate bound-state conformations in solution which resulted in the generation of a potent eIF4E binder.
The study illustrates the molecular basis of eIF4E recognition by a disordered epitope from eIF4G and its modulation to generate peptides that can potentially attenuate translation initiation in oncology.
蛋白质中的无序区域（IDR）可以通过促进蛋白质-蛋白质相互作用（PPIs）来调节其活性，例如真核翻译起始因子 4E（eIF4E）蛋白被蛋白质 eIF4G 招募。该 PPI 模块的失调是广泛的癌症相关恶性肿瘤的核心，通过生物活性肽靶向抑制该模块是一种有前途的治疗干预策略。
我们采用分子动力学模拟结合生物物理测定，通过引入促进无序到有序转变的非天然氨基酸，从内在无序的 eIF4G 支架上合理开发肽衍生物。
这些肽的构象异质性和采用与 eIF4E 最佳相互作用模式所需的结构重排程度突出了它们的差异结合亲和力。在结构集合中存在预结构化的局部螺旋元件对于肽在蛋白质表面上的有效对接至关重要。肽与 eIF4E 之间的 Y4：P38 氢键相互作用的形成是有效识别蛋白质的限速事件，因为它发生在肽的无序区域。
这些见解被进一步用于设计肽中的特征，以在溶液中传播结合态构象，从而产生有效的 eIF4E 结合物。
该研究说明了 eIF4E 识别 eIF4G 无序表位的分子基础及其调节，以产生潜在的抗肿瘤翻译起始抑制剂。
