Inactivation of p53 is found in over 50% of all cancers; p53 disfunction is often caused by a single missense mutation localized in the DNA binding domain (DBD). Rescue mutants N235K and N239Y stabilize and restore function to multiple p53 cancer mutants. Here, we use NMR to compare protein dynamics between WT and rescue mutants to understand the mechanism of stabilization. We measured and compared folding dynamics by calculating protection factors (PFs) from NMR hydrogen exchange rates of backbone amides. We find that both rescue mutants impose a global stabilizing effect that dampens their motions compared to WT DBD, predominantly in the beta-sandwich. However, a few regions become more flexible in rescue mutants. Notably, positions that have increased PFs map to cancer mutants rescued by each mutant. We also compared relaxation results to obtain flexibility information in the ps to ns timescale regime. Protein sequence analysis was used to determine the occurrence of these rescue mutants in nature and showed that 235K is found in mice and rats, but there is no evidence of 239Y occurring naturally in any species. Understanding the mechanism by which stabilizing mutants rescue p53 may reveal novel avenues for the development of cancer therapeutics. Our findings suggest that cancer therapeutics aimed at restoring p53 function could consider protein dynamics as a metric of drug efficacy.

中文翻译：

---

核磁共振氢交换和弛豫揭示了由p53救援突变体N239Y和N235K稳定的位置。

在所有癌症中，有超过50％的人发现p53失活。p53功能障碍通常是由位于DNA结合域（DBD）中的单个错义突变引起的。救援突变体N235K和N239Y稳定并恢复了多个p53癌症突变体的功能。在这里，我们使用NMR比较WT和救援突变体之间的蛋白质动力学，以了解稳定机制。我们通过计算主链酰胺的NMR氢交换速率的保护因子（PF）来测量和比较折叠动力学。我们发现，与WT DBD相比，这两个抢救突变体均具有全局稳定作用，从而抑制了它们的运动，主要是在β三明治中。但是，一些区域在救援突变体中变得更加灵活。值得注意的是，PFs增加的位置对应于每个突变体挽救的癌症突变体。我们还比较了松弛结果，从而获得了ps至ns时标范围内的灵活性信息。蛋白序列分析被用于确定这些拯救突变体在自然界中的发生，并表明在小鼠和大鼠中发现了235K，但没有证据表明任何物种中自然存在239Y。了解稳定突变体拯救p53的机制可能会揭示癌症治疗药物开发的新途径。我们的发现表明，旨在恢复p53功能的癌症治疗方法可以将蛋白质动力学视为药物疗效的量度。但是没有证据表明239Y在任何物种中自然发生。了解稳定突变体拯救p53的机制可能会揭示癌症治疗药物开发的新途径。我们的发现表明，旨在恢复p53功能的癌症治疗方法可以将蛋白质动力学视为药物疗效的量度。但是没有证据表明239Y在任何物种中自然发生。了解稳定突变体拯救p53的机制可能会揭示癌症治疗药物开发的新途径。我们的发现表明，旨在恢复p53功能的癌症治疗方法可以将蛋白质动力学视为药物疗效的量度。