The effects of para-chloromercuribenzoic acid and different oxidative and sulfhydryl agents on a novel, non-AT1, non-AT2 angiotensin binding site identified as neurolysin.
The effects of para-chloromercuribenzoic acid and different oxidative and sulfhydryl agents on a novel, non-AT1, non-AT2 angiotensin binding site identified as neurolysin.
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DOI：
10.1016/j.regpep.2013.03.021
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发表时间：
2013-06-10
影响因子：
--
通讯作者：
Speth RC
中科院分区：
文献类型：
--
作者：
Santos KL;Vento MA;Wright JW;Speth RC
血管紧张素肽的一种新的、非at1、非at2脑结合位点被对氯脲苯甲酸酯（PCMB）发现，这是一种神经溶解素的膜相关变体。目前研究了不同的有机和无机氧化和巯基活性物质揭示或抑制125I-Sar1Ile8血管紧张素II （SI-Ang II）与该位点结合的能力。在含有氯沙坦（10 μM）和PD123319 （10 μM）加100 μM PCMB的缓冲液中培养的大鼠脑和睾丸匀浆组织膜中，39种化合物中有5种抑制了125I-SI Ang II在脑和睾丸中的结合。汞酰酸、氯化汞（HgCl2）和硝酸银（AgNO3）最有效地抑制了125I-SI Ang II与IC50 ~ 1-20 μM的结合。基于HgCl2对脑室内给药Ang II和125I-SI Ang II与肝脏AT1受体结合的致病变作用缺乏影响，HgCl2的抑制作用与HgCl2与血管紧张素II （Ang II）的相互作用无关。在巯基试剂中，半胱胺和还原型谷胱甘肽（GSH），而不是氧化谷胱甘肽（GSSG），抑制pcmb - 125I-SI Ang II在脑和睾丸中的结合。硫柳汞和4-羟基汞苯甲酸盐在100 μM下适度抑制pcmb -揭露125I-SI Ang II在脑和睾丸的结合；然而，他们也发现了独立于PCMB的非at1、非at2结合。4-羟基苯甲酸没有促进125 I-SI Ang II与该结合位点的结合，表明只有特定的有机化合物才能揭开结合位点。所有这些相互作用物质的共同点是与蛋白质半胱氨酸硫结合的能力。神经溶素与密切相关的硫柳寡肽酶之间的半胱氨酸比较显示，在拟议的配体结合通道（Brown et al., 2001）中，神经溶素活性位点附近有一个非保守的半胱氨酸（cys650，基于全长变体）。我们提出PCMB和密切相关的有机化合物中的汞离子与cys650结合，而酸性阴离子与附近的精氨酸或赖氨酸沿着通道形成离子键，从而影响神经溶解素的构象变化，促进Ang II结合。
A novel, non-AT1, non-AT2 brain binding site for angiotensin peptides that is unmasked by p-chloromercuribenzoate (PCMB) has been identified as a membrane associated variant of neurolysin. The ability of different organic and inorganic oxidative and sulfhydryl reactive agents to unmask or inhibit 125I-Sar1Ile8 angiotensin II (SI-Ang II) binding to this site was presently examined. In tissue membranes from homogenates of rat brain and testis incubated in assay buffer containing losartan (10 μM) and PD123319 (10 μM) plus 100 μM PCMB, 5 of the 39 compounds tested inhibited 125I-SI Ang II binding in brain and testis. Mersalyl acid, mercuric chloride (HgCl2) and silver nitrate (AgNO3) most potently inhibited 125I-SI Ang II binding with IC50’s ~1–20 μM This HgCl2 inhibition was independent of any interaction of HgCl2 with angiotensin II (Ang II) based on the lack of effect of HgCl2 on the dipsogenic effects of intracerebroventricularly administered Ang II and 125I-SI Ang II binding to AT1 receptors in the liver. Among sulfhydryl reagents, cysteamine and reduced glutathione (GSH), but not oxidized glutathione (GSSG) up to 1 mM, inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis. Thimerosal and 4-hydroxymercuribenzoate moderately inhibited PCMB-unmasked 125I-SI Ang II binding in brain and testis at 100 μM; however, they also unmasked non-AT1, non-AT2 binding independent of PCMB. 4-hydroxybenzoic acid did not promote 125 I-SI Ang II binding to this binding site indicating that only specific organomercurial compounds can unmask the binding site. The common denominator for all of these interacting substances is the ability to bind to protein cysteine sulfur. Comparison of cysteines between neurolysin and the closely related enzyme thimet oligopeptidase revealed an unconserved cysteine (cys650, based on the full length variant) in the proposed ligand binding channel (Brown et al., 2001) near the active site of neurolysin. It is proposed that the mercuric ion in PCMB and closely related organomercurial compounds binds to cys650, while the acidic anion forms an ionic bond with a nearby arginine or lysine along the channel to effect a conformational change in neurolysin that promotes Ang II binding.
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DOI：
10.1111/j.1432-1033.1992.tb17168.x
发表时间：
1992-08-15
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
DAHMS, P;MENTLEIN, R
通讯作者：
MENTLEIN, R
影响因子：
2.9
作者：
Karamyan, Vardan T.;Speth, Robert C.
通讯作者：
Speth, Robert C.
影响因子：
4.8
作者：
Cook, JVF;McGregor, A;Eidne, KA
通讯作者：
Eidne, KA
影响因子：
64.8
作者：
HUNTER, WM;GREENWOOD, FC
通讯作者：
GREENWOOD, FC
影响因子：
20.1
作者：
Donoghue, M;Hsieh, F;Acton, S
通讯作者：
Acton, S