Department of Chemistry, Emory University, Atlanta, GA 30322, United States.
J Inorg Biochem. 2013 Oct;127:7-12. doi: 10.1016/j.jinorgbio.2013.06.004. Epub 2013 Jun 15.
The role of π-stacking in controlling redox and ligand binding properties of porphyrins has been of interest for many years. The recent discovery of H-NOX domains has provided a model system to investigate the role of porphyrin π-stacking within a heme protein scaffold. Removal of a phenylalanine-porphyrin π-stack dramatically increased O2, NO, and CO affinities and caused changes in redox potential (~40mV) without any structural changes. These results suggest that small changes in redox potential affect ligand affinity and that π-stacking may provide a novel route to engineer heme protein properties for new functions.
π-堆积在控制卟啉的氧化还原和配体结合性质方面多年来一直受到关注。最近发现的 H-NOX 结构域为研究血红素蛋白支架内卟啉 π-堆积的作用提供了一个模型系统。去除一个苯丙氨酸-卟啉 π-堆积显著增加了 O2、NO 和 CO 的亲和力，并导致氧化还原电位发生变化（约 40mV），而没有任何结构变化。这些结果表明，氧化还原电位的微小变化会影响配体亲和力，而 π-堆积可能为工程血红素蛋白特性以实现新功能提供一种新途径。
