Nicolini Federica, Todorovski Toni, Puig Eduard, Díaz-Lobo Mireia, Vilaseca Marta, García Jesús, Andreu David, Giralt Ernest
Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, 08028 Barcelona, Spain.
Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona Biomedical Research Park, Dr. Aiguader 88, 08003 Barcelona, Spain.
Curr Issues Mol Biol. 2023 Jun 7;45(6):4985-5004. doi: 10.3390/cimb45060317.
Tumour suppressor p53 plays a key role in the development of cancer and has therefore been widely studied in recent decades. While it is well known that p53 is biologically active as a tetramer, the tetramerisation mechanism is still not completely understood. p53 is mutated in nearly 50% of cancers, and mutations can alter the oligomeric state of the protein, having an impact on the biological function of the protein and on cell fate decisions. Here, we describe the effects of a number of representative cancer-related mutations on tetramerisation domain (TD) oligomerisation defining a peptide length that permits having a folded and structured domain, thus avoiding the effect of the flanking regions and the net charges at the - and -terminus. These peptides have been studied under different experimental conditions. We have applied a variety of techniques, including circular dichroism (CD), native mass spectrometry (MS) and high-field solution NMR. Native MS allows us to detect the native state of complexes maintaining the peptide complexes intact in the gas phase; the secondary and quaternary structures were analysed in solution by NMR, and the oligomeric forms were assigned by diffusion NMR experiments. A significant destabilising effect and a variable monomer population were observed for all the mutants studied.
肿瘤抑制蛋白p53在癌症发展中起关键作用，因此在近几十年中受到了广泛研究。虽然众所周知p53作为四聚体具有生物学活性，但其四聚化机制仍未完全阐明。在近50%的癌症中p53发生了突变，这些突变会改变蛋白质的寡聚状态，进而影响蛋白质的生物学功能以及细胞命运的决定。在此，我们描述了一些具有代表性的癌症相关突变对四聚化结构域（TD）寡聚化的影响，确定了一个允许形成折叠和结构化结构域的肽长度，从而避免侧翼区域以及N端和C端净电荷的影响。这些肽已在不同实验条件下进行了研究。我们应用了多种技术，包括圆二色性（CD）、基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）和高场溶液核磁共振（NMR）。基质辅助激光解吸电离飞行时间质谱使我们能够检测复合物的天然状态，在气相中保持肽复合物完整无损；通过核磁共振在溶液中分析二级和四级结构，并通过扩散核磁共振实验确定寡聚形式。对于所有研究的突变体，均观察到了显著的去稳定作用和可变的单体群体。
