Extended peptide-based inhibitors efficiently target the proteasome and reveal overlapping specificities of the catalytic β-subunits
Extended peptide-based inhibitors efficiently target the proteasome and reveal overlapping specificities of the catalytic β-subunits
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DOI：
10.1016/s1074-5521(01)00069-2
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发表时间：
2001-09-01
影响因子：
--
通讯作者：
Overkleeft, HS
中科院分区：
文献类型：
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作者：
Kessler, BM;Tortorella, D;Overkleeft, HS
背景：26 S蛋白酶体负责大多数胞质蛋白质的水解。并且是主要组织相容性复合体I类介导的抗原呈递中的重要蛋白酶。来自哺乳动物来源的组成型表达的蛋白酶体具有三种不同的催化活性物质β 1、β 2和β 5，它们在γ-干扰素诱导的免疫蛋白酶体中分别被一组不同的催化亚基β 11、β 21和β 51取代。基于短荧光肽底物的优选切割，蛋白酶体的活性已被分配给各个亚基，并分类为“胰凝乳蛋白酶样”（β 5）、“胰蛋白酶样”（β 2）和“肽基-谷氨酰肽水解”（β 1）。对蛋白质底物的研究表明了一种复杂得多、不那么严格的切割偏好。我们的理由是，扩展大小的抑制剂将深入了解重叠的个别活动和subunity.Results的底物特异性的程度：一类新的蛋白酶体抑制剂，相当大的扩展比较常用的荧光底物和肽基抑制剂，已制备。安全捕获树脂的应用允许使用固相方案产生目标化合物。新化合物的评价揭示了一组高效的蛋白酶体抑制剂，其以相当的亲和力靶向所有单个活性亚基，与迄今为止描述的其他抑制剂不同。修饰的最活跃的化合物，金刚烷-乙酰基（6-氨基己酰基）（3）-（亮氨酰基）（3）-乙烯基-（甲基）-砜（Ada-Ahx（3）L（3）VS），本身能够在活细胞中的蛋白酶体抑制，提供了一套新的放射性和亲和labels.Conclusions：N-末端延伸的肽乙烯基砜具有深远的影响，其效率和选择性作为蛋白酶体抑制剂。这种延伸大大增强了抑制作用，并在很大程度上消除了对单个催化活性的选择性。我们的结论是，与较大的基板的相互作用，似乎是歧视不同的基板序列的催化活性比通常假设的基础上使用的小肽为基础的基板和抑制剂。本文所述的化合物易于合成，并且在活细胞中比它们的短肽乙烯砜对应物更有效的抑制剂。(C)2001爱思唯尔科技有限公司版权所有。
Background: The 26S proteasome is responsible for most cytosolic proteolysis. and is an important protease in major histocompatibility complex class I-mediated antigen presentation. Constitutively expressed proteasomes from mammalian sources possess three distinct catalytically active species, beta1, beta2 and beta5, which are replaced in the gamma -interferon-inducible immunoproteasome by a different set of catalytic subunits, beta li, beta 2i and beta 5i, respectively. Based on preferred cleavage of short fluorogenic peptide substrates, activities of the proteasome have been assigned to individual subunits and classified as 'chymotryptic-like' (beta5), 'tryptic-like' (beta2) and 'peptidyl-glutamyl peptide hydrolyzing' (beta1). Studies with protein substrates indicate a far more complicated, less strict cleavage preference. We reasoned that inhibitors of extended size would give insight into the extent of overlapping substrate specificity of the individual activities and subunits.Results: A new class of proteasome inhibitors, considerably extended in comparison with the commonly used fluorescent substrates and peptide-based inhibitors, has been prepared. Application of the safety catch resin allowed the generation of the target compounds using a solid phase protocol, Evaluation of the new compounds revealed a set of highly potent proteasome inhibitors that target all individual active subunits with comparable affinity, unlike the other inhibitors described to date. Modification of the most active compound, adamantane-acetyl(6-aminohexanoyl)(3)-(leucinyl)(3)-vinyl-(methyl)-sulfone (Ada-Ahx(3)L(3)VS), itself capable of proteasome inhibition in living cells, afforded a new set of radio- and affinity labels.Conclusions: N-terminal extension of peptide vinyl sulfones has a profound influence on both their efficiency and selectivity as proteasome inhibitors. Such extensions greatly enhance inhibition and largely obliterate selectivity towards the individual catalytic activities. We conclude that for the interaction with larger substrates, there appears to be less discrimination of different substrate sequences for the catalytic activities than is normally assumed based on the use of small peptide-based substrates and inhibitors. The compounds described here are readily accessible synthetically, and are more potent inhibitors in living cells than their shorter peptide vinyl sulfone counterparts. (C) 2001 Elsevier Science Ltd. All rights reserved.