Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
J Am Chem Soc. 2013 Aug 28;135(34):12869-76. doi: 10.1021/ja406399r. Epub 2013 Aug 19.
Caspases are a family of cysteine-aspartyl proteases that are well recognized for their essential roles in apoptosis and inflammation. Recently, caspases have also been linked to the promotion of other biologically important phenomena, such as cellular differentiation and proliferation. Dysregulation of the multifaceted and indispensable activities of caspases has been globally linked to several diseases, including cancer and neurodegenerative disorders; however, the specific caspase members responsible for these diseases have yet to be assigned. Activity-based probes (ABPs) and peptide-based inhibitors are instrumental in the detection and control of protease activity and serve as alternative methods to genetic approaches. Such molecules aid in the interrogation of specific proteases within cellular and animal models as well as help elucidate aberrant proteolytic function correlated to disease phenotypes. No ABPs or inhibitors have been discovered that specifically target one of the eleven human caspases in a cellular context. Therefore, ascribing distinct contributions to an individual caspase activity within naturally occurring biological systems is not possible. Herein, we describe a peptide series optimized for the selective detection and inhibition of active caspase-3 in cells. These compounds exhibit low nanomolar potency against caspase-3 with >120-fold selectivity over caspase-7 which shares 77% active site identity. Our ability to individually target wild-type active caspase-3 for detection and cell permeable inhibition is a valuable proof-of-concept methodology that can be readily employed to probe the significance of caspase-3 in apoptosis, neurological disorders, cardiovascular diseases, and sepsis.
半胱天冬酶是一组半胱氨酸天冬氨酸蛋白酶，它们在细胞凋亡和炎症中发挥着重要作用，这一点已得到广泛认可。最近，半胱天冬酶还与促进细胞分化和增殖等其他生物学上重要的现象有关。半胱天冬酶的多方面和不可或缺的活性失调与包括癌症和神经退行性疾病在内的多种疾病密切相关；然而，导致这些疾病的特定半胱天冬酶成员尚未确定。基于活性的探针 (ABPs) 和肽类抑制剂对半胱天冬蛋白酶活性的检测和控制至关重要，是遗传方法的替代方法。这些分子有助于在细胞和动物模型中研究特定的蛋白酶，并有助于阐明与疾病表型相关的异常蛋白水解功能。在细胞环境中，尚未发现专门针对十一种人类半胱天冬酶之一的 ABPs 或抑制剂。因此，在自然发生的生物系统中，不可能将特定的贡献归因于单个半胱天冬酶的活性。在此，我们描述了一个优化的肽系列，用于在细胞中选择性检测和抑制活性半胱天冬酶-3。这些化合物对半胱天冬酶-3 的抑制活性达到纳摩尔级，对具有 77%活性位点同一性的半胱天冬酶-7 的选择性超过 120 倍。我们能够单独针对野生型活性半胱天冬酶-3 进行检测和细胞渗透性抑制，这是一种有价值的概念验证方法，可用于研究半胱天冬酶-3 在细胞凋亡、神经疾病、心血管疾病和败血症中的意义。
