Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity.
Post-translational modification of glutamine and lysine residues of HIV-1 aspartyl protease by transglutaminase increases its catalytic activity.
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通过转谷氨酰胺酶对 HIV-1 天冬氨酰蛋白酶的谷氨酰胺和赖氨酸残基进行翻译后修饰可增加其催化活性。
DOI：
10.1016/j.bbrc.2010.02.060
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发表时间：
2010
影响因子：
3.1
通讯作者：
S. Beninati
中科院分区：
文献类型：
--
作者：
A. Lentini;C. Tabolacci;S. Melino;B. Provenzano;S. Beninati
人类免疫缺陷病毒1型乙酰基蛋白酶（HIV-1 PR）是一种病毒复制所需的同型二聚体乙酰基内肽酶。HIV-1 PR显示出作为豚鼠肝转氨酶（TG，EC 2.3.2.13）和人因子XIIIa的酰基供体和受体的体外作用。这些初步证据表明，HIV-1 PR含有至少三个TG反应性的乙酰氨基和一个赖氨酰残基。我们在这里报告说，孵育的HIV-1 PR与TG增加其催化活性。这种增加取决于孵育时间、TG浓度和Ca 2+的存在。TG修饰的HIV-1 PR的蛋白水解消化物中ε-（γ-谷氨酰）赖氨酸的鉴定表明该蛋白酶的分子内共价交联，这可能促进该酶的非共价二聚化和随后通过构象变化的活化。这一假设得到以下观察结果的支持：TG催化的HIV-1 PR活化被亚精胺（SPD）完全消除，亚精胺（SPD）作为ε-（γ-谷氨酰）赖氨酸形成的竞争性抑制剂。事实上，在ImM SPD的存在下，异肽的形成减少了约80%。在SPD存在下，TG催化的HIV-1 PR修饰的主要产物是N1-单（γ-谷氨酰基）SPD和N8-单（γ-谷氨酰基）SPD。N1，N8-双（γ-谷氨酰）SPD的含量可忽略不计，这些结果对通过翻译后修饰激活蛋白酶和设计潜在的抑制剂具有重要意义。
The human immunodeficiency virus type 1 aspartyl protease (HIV-1 PR) is a homodimeric aspartyl endopeptidase that is required for virus replication. HIV-1 PR was shown to act invitro as acyl-donor and -acceptor for both guinea pig liver transglutaminase (TG, EC 2.3.2.13) and human Factor XIIIa. These preliminary evidences suggested that the HIV-1 PR contains at least three TG-reactive glutaminyl and one lysyl residues. We report here that the incubation of HIV-1 PR with TG increases its catalytic activity. This increase is dependent upon the time of incubation, the concentration of TG and the presence of Ca2+. Identification of ε-(γ-glutamyl)lysine in the proteolytic digest of the TG-modified HIV-1 PR suggested intramolecular covalent cross-linking of this protease which may promote a non-covalent dimerization and subsequent activation of this enzyme via a conformational change. This hypothesis is supported by the observation that the TG-catalyzed activation of HIV-1 PR was completely abolished by spermidine (SPD) which acts as a competitive inhibitor of ε-(γ-glutamyl)lysine formation. Indeed, in the presence of 1mM SPD the formation of the isopeptide was decreased of about 80%. The main products of the TG-catalyzed modification of HIV-1 PR in the presence of SPD were N1-mono(γ-glutamyl)SPD and N8-mono(γ-glutamyl)SPD. Negligible amount of N1,N8-bis(γ-glutamyl)SPD were found. The significance of these results is discussed with respect to the activation of the protease by post-translational modification and design of potential inhibitors.
转谷氨酰胺酶及其调节：对多胺代谢的影响。
影响因子：
--
作者：
Davies,PJ;Chiocca,EA;Basilion,JP;Poddar,S;Stein,JP
通讯作者：
Stein,JP
影响因子：
5.6
作者：
M. Todd;N. Semo;E. Freire
通讯作者：
M. Todd;N. Semo;E. Freire