Substrate and inhibitor specificity of interleukin-1 beta-converting enzyme and related caspases
Substrate and inhibitor specificity of interleukin-1 beta-converting enzyme and related caspases
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DOI：
10.1074/jbc.272.11.7223
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发表时间：
1997-03-14
影响因子：
4.8
通讯作者：
Livingston, DJ
中科院分区：
文献类型：
--
作者：
Margolin, N;Raybuck, SA;Livingston, DJ
白细胞介素-1 β转化酶（ICE）是一种新型半胱氨酸蛋白酶，负责将前白细胞介素-1 β（前IL-1 β）裂解为成熟细胞因子，是相关蛋白酶（半胱天冬酶）家族的成员，包括秀丽隐杆线虫细胞死亡基因产物CED-3。除了它们的序列同源性之外，这些半胱氨酸蛋白酶对具有P-1天冬氨酸残基的肽基序列显示出不寻常的底物特异性。我们已经检查了ICE及其三种同系物TX、CPP-32和CMH-1将前IL-1 β加工成成熟形式的动力学。在ICE同系物中，只有TX处理前IL-1 β，尽管其催化效率比ICE本身低250倍。我们还研究了这四种蛋白酶处理聚（ADP-核糖）聚合酶的能力，聚（ADP-核糖）聚合酶是一种DNA修复酶，在细胞凋亡发生后几分钟内被切割。检测的每种半胱天冬酶都切割PARP，催化效率范围为2.3 x 10（6）M（-1）S-1（CPP 32）至1.0 x 10（3）M（-1）S-1（TX）。此外，我们报告了几种可逆抑制剂和不可逆灭活剂的动力学常数，这些抑制剂和灭活剂已被用于在凋亡蛋白水解级联反应中涉及一种或多种半胱天冬酶。Ac-Asp-Glu-Val-Asp醛（DEVD-CHO）是CPP-32的有效抑制剂，Ki值为0.5 nM，但也是CMH-1（Ki = 35 nM）和ICE（Ki = 15 nM）的有效抑制剂。本文呈现的与ICE络合的DEVD-CHO的X射线晶体结构揭示了Ac-YVAD-CHO共络合物结构中不存在的静电相互作用（Wilson，K. P.，布莱克，J。A. F.、汤姆森，J. A.，Kim，E. E、格里菲斯，J. P.，Navia，M.一、Murcko，M. A，Chambers，S. P.，阿尔达佩河一、Raybuck，S.一、和利文斯顿，D. J.（1994）Nature 370，270-275），解释了该抑制剂对ICE的惊人效力。
Interleukin-1 beta-converting enzyme (ICE) is a novel cysteine protease responsible for the cleavage of pre-interleukin-1 beta (pre-IL-1 beta) to the mature cytokine and a member of a family of related proteases (the caspases) that includes the Caenorhabditis elegans cell death gene product, CED-3. In addition to their sequence homology, these cysteine proteases display an unusual substrate specificity for peptidyl sequences with a P-1 aspartate residue. We have examined the kinetics of processing pre-IL-1 beta to the mature form by ICE and three of its homologs, TX, CPP-32, and CMH-1. Of the ICE homologs, only TX processes pre-IL-1 beta, albeit with a catalytic efficiency 250-fold less than ICE itself. We also investigated the ability of these four proteases to process poly(ADP-ribose) polymerase, a DNA repair enzyme that is cleaved within minutes of the onset of apoptosis. Every caspase examined cleaves PARP, with catalytic efficiencies ranging from 2.3 x 10(6) M(-1) S-1 for CPP32 to 1.0 x 10(3) M(-1) S-1 for TX. In addition, we report kinetic constants for several reversible inhibitors and irreversible inactivators, which have been used to implicate one or more caspases in the apoptotic proteolysis cascade. Ac-Asp-Glu-Val-Asp aldehyde (DEVD-CHO) is a potent inhibitor of CPP-32 with a K-i value of 0.5 nM, but is also potent as inhibitor of CMH-1 (K-i = 35 nM) and ICE (K-i = 15 nM). The x-ray crystal structure of DEVD-CHO complexed to ICE presented here reveals electrostatic interactions not present in the Ac-YVAD-CHO co-complex structure (Wilson, K. P., Black, J.-A. F., Thomson, J. A., Kim, E. E., Griffith, J. P., Navia, M. A., Murcko, M. A, Chambers, S. P., Aldape, R. A., Raybuck, S. A., and Livingston, D. J. (1994) Nature 370, 270-275), accounting for the surprising potency of this inhibitor against ICE.