Energetics-based protein profiling on a proteomic scale: identification of proteins resistant to proteolysis.
Energetics-based protein profiling on a proteomic scale: identification of proteins resistant to proteolysis.
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DOI：
10.1016/j.jmb.2007.02.091
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发表时间：
2007-05
影响因子：
5.6
通讯作者：
Chiwook Park;Sharleen Zhou;J. Gilmore;S. Marqusee
中科院分区：
文献类型：
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作者：
Chiwook Park;Sharleen Zhou;J. Gilmore;S. Marqusee
蛋白质的天然状态是灵活的，不仅仅是独特的天然构象。能量学和动力学从这个构象合奏所产生的内在联系蛋白质的功能和调节。蛋白水解敏感性是由这种构象能量景观决定的一个特征。作为一种尝试，研究能量的蛋白质在蛋白质组学的规模，我们挑战了大肠杆菌蛋白质组与广泛的蛋白质水解，并确定哪些蛋白质，如果有的话，优化了他们的能量景观抗蛋白质水解。令我们惊讶的是，多种可溶性蛋白在挑战中幸存下来。麦芽糖结合蛋白，从嗜热菌蛋白酶消化的幸存者，其特征在于在体外生物物理研究，以确定蛋白水解抗性的物理起源。该实验表征表明，动力学稳定性是麦芽糖结合蛋白中不寻常抗性的原因。鉴定的幸存者的生化功能表明，这些蛋白质中的许多可能已经进化出极端的蛋白水解抗性，因为它们在应激条件下的关键作用。我们的研究结果表明，功能选择下的蛋白质可以进化极端的蛋白水解阻力，通过调节其构象能量景观，而不需要发明新的折叠，蛋白质可以在蛋白质组学规模上，根据其能量特性，通过使用蛋白水解作为结构探针。
Native states of proteins are flexible, populating more than just the unique native conformation. The energetics and dynamics resulting from this conformational ensemble are inherently linked to protein function and regulation. Proteolytic susceptibility is one feature determined by this conformational energy landscape. As an attempt to investigate energetics of proteins on a proteomic scale, we challenged the Escherichia coli proteome with extensive proteolysis and determined which proteins, if any, have optimized their energy landscape for resistance to proteolysis. To our surprise, multiple soluble proteins survived the challenge. Maltose binding protein, a survivor from thermolysin digestion, was characterized by in vitro biophysical studies to identify the physical origin of proteolytic resistance. This experimental characterization shows that kinetic stability is responsible for the unusual resistance in maltose binding protein. The biochemical functions of the identified survivors suggest that many of these proteins may have evolved extreme proteolytic resistance because of their critical roles under stressed conditions. Our results suggest that under functional selection proteins can evolve extreme proteolysis resistance by modulating their conformational energy landscapes without the need to invent new folds, and that proteins can be profiled on a proteomic scale according to their energetic properties by using proteolysis as a structural probe.