Caspase的活化及其在细胞凋亡中的作用

Caspase是执行细胞凋亡的主要酶类，目前已鉴定的哺乳动物Caspase有14种。Caspase以酶原的形式合成，催化活性很低，必须激活以后才能发挥作用。活化的Caspase通过特异性的裂解一套底物而导致细胞凋亡。与Caspase有关的细胞凋亡通路至少有三种：线粒体／细胞色素c通路、死亡受体通路和内质网通路。Caspase总是与其抑制剂共存，以防止Caspase酶原意外激活而对正常细胞造成损伤。

Activation and Function of Caspases in Apoptosis

Caspases are the key executioners of apoptosis. Up to now at least 14 mammalian caspases have been identified. Caspases are synthesized as zymogens that have very low catalytic activity. The zymogens can be activated and active caspases specifically cleavage a set of substrates and then lead to apoptosis. There are at least three distinct apoptosis pathways involved in caspases: mitochondrial/cytochrome C, death receptor and endoplasmic reticulum mediated apoptosis pathways. Caspases and their inhibitors always coexist lest that caspases are activated accidentally and hurt the normal cells.