Warren Jeffrey J, Gray Harry B, Winkler Jay R, Kozak John J
Beckman Institute, California Institute of Technology, Pasadena CA 91125.
Mol Phys. 2013 Apr 1;111(7):922-929. doi: 10.1080/00268976.2012.758324.
We investigate the stability to structural perturbation of azurin using a previously developed geometric model. Our analysis considers Ru(2,2',6',2″-terpyridine)(1,10-phenanthroline)(His83)-labeled wild-type azurin and five variants with mutations to Cu-ligating residues. We find that in the early stages of unfolding, the β-strands exhibit the most structural stability. The conserved residues comprising the hydrophobic core are dislocated only after nearly complete unfolding of the β-barrel. Attachment of the Ru-complex at His83 does not destabilize the protein fold, despite causing some degree of structural rearrangement. Notably, replacing the Cys112 and/or Met121 Cu ligands does not affect the conformational integrity of the protein. Notably, these results are in accord with experimental evidence, as well as molecular dynamics simulations of the denaturation of azurin.
我们使用先前开发的几何模型研究了天青蛋白对结构扰动的稳定性。我们的分析考虑了用钌（2,2',6',2″-三联吡啶）（1,10-菲咯啉）（His83）标记的野生型天青蛋白以及五个铜配位残基发生突变的变体。我们发现，在去折叠的早期阶段，β链表现出最高的结构稳定性。构成疏水核心的保守残基仅在β桶几乎完全去折叠后才发生位移。尽管在His83处连接钌配合物会引起一定程度的结构重排，但并不会使蛋白质折叠不稳定。值得注意的是，替换Cys112和/或Met121铜配体不会影响蛋白质的构象完整性。值得注意的是，这些结果与实验证据以及天青蛋白变性的分子动力学模拟结果一致。
