An Optimized Activity-Based Probe for the Study of Caspase-6 Activation
An Optimized Activity-Based Probe for the Study of Caspase-6 Activation
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DOI：
10.1016/j.chembiol.2011.12.021
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发表时间：
2012-03-23
影响因子：
--
通讯作者：
Bogyo, Matthew
中科院分区：
文献类型：
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作者：
Edgington, Laura E.;van Raam, Bram J.;Bogyo, Matthew
虽然已经做出了重大的努力，以了解在细胞凋亡过程中的caspase激活的机制，许多问题仍然是关于如何以及何时执行caspase得到激活。我们描述了一种基于活性的探针的设计和合成，该探针标记半胱天冬酶-3/-6/-7，允许同时直接监测所有的刽子手半胱天冬酶。与我们先前报道的探针AB 50相比，该探针具有增强的体内性质和降低的交叉反应性。使用这种探针，我们发现，caspase-6经历了构象变化，可以结合底物，即使在没有切割的酶原。我们还证明，caspase-6的激活不需要活性caspase-3/-7，这表明它可以自动激活或被其他蛋白酶切割。总之，我们的研究结果表明，caspase-6激活通过一种独特的机制进行，这可能是重要的，其不同的生物学功能。
Although significant efforts have been made to understand the mechanisms of caspase activation during apoptosis, many questions remain regarding how and when executioner caspases get activated. We describe the design and synthesis of an activity-based probe that labels caspase-3/-6/-7, allowing direct monitoring of all executioner caspases simultaneously. This probe has enhanced in vivo properties and reduced cross-reactivity compared to our previously reported probe, AB50. Using this probe, we find that caspase-6 undergoes a conformational change and can bind substrates even in the absence of cleavage of the proenzyme. We also demonstrate that caspase-6 activation does not require active caspase-3/-7, suggesting that it may autoactivate or be cleaved by other proteases. Together, our results suggest that caspase-6 activation proceeds through a unique mechanism that may be important for its diverse biological functions.