Kinetic instability of p53 core domain mutants - Implications for rescue by small molecules
Kinetic instability of p53 core domain mutants - Implications for rescue by small molecules
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DOI：
10.1074/jbc.m302458200
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发表时间：
2003-06-27
影响因子：
4.8
通讯作者：
Fersht, AR
中科院分区：
文献类型：
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作者：
Friedler, A;Veprintsev, DB;Fersht, AR
肿瘤抑制蛋白p53中的致癌突变主要发现于其DNA结合核心结构域。这些突变体中的许多在体温下是不稳定的。在这里我们展示了这些突变体在37摄氏度下也能在几分钟内变性。野生型p53核心结构域解折叠的半衰期（t（1/2））为9分钟。随着热力学不稳定性的增加，热点突变体变性更快。高度不稳定的突变体I195 T的t（1/2）小于1分钟。野生型p53-（94-360）构建体，含有核心和四聚化结构域，更稳定，t（1/2）= 37分钟，在37 ℃，类似于全长p53。解折叠后，变性蛋白质聚集，速率随蛋白质浓度的增加而增加。p53稳定肽CDB 3的衍生物显著减慢了p53核心结构域的解折叠速率。药物如CDB 3，拯救p53的不稳定突变体的构象，必须在生物合成期间或之后立即起作用。它们应该使突变蛋白保持折叠构象并防止其聚集，使其有足够的时间到达细胞核并结合其序列特异性靶DNA或将其稳定的p53结合蛋白。
Oncogenic mutations in the tumor suppressor protein p53 are found mainly in its DNA-binding core domain. Many of these mutants are thermodynamically unstable at body temperature. Here we show that these mutants also denature within minutes at 37 degreesC. The half-life (t(1/2)) of the unfolding of wild-type p53 core domain was 9 min. Hot spot mutants denatured more rapidly with increasing thermodynamic instability. The highly destabilized mutant I195T had a t(1/2) of less than 1 min. The wild-type p53-(94-360) construct, containing the core and tetramerization domains, was more stable, with t(1/2) = 37 min at 37 degreesC, similar to full-length p53. After unfolding, the denatured proteins aggregated, the rate increasing with higher concentrations of protein. A derivative of the p53-stabilizing peptide CDB3 significantly slowed down the unfolding rate of the p53 core domain. Drugs such as CDB3, which rescue the conformation of unstable mutants of p53, have to act during or immediately after biosynthesis. They should maintain the mutant protein in a folded conformation and prevent its aggregation, allowing it enough time to reach the nucleus and bind its sequence-specific target DNA or the p53 binding proteins that will stabilize it.