Interaction of soluble guanylate cyclase with YC-1: Kinetic and resonance Raman studies
Interaction of soluble guanylate cyclase with YC-1: Kinetic and resonance Raman studies
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DOI：
10.1021/bi992332q
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发表时间：
2000-04-11
期刊：
影响因子：
2.9
通讯作者：
Marletta, MA
中科院分区：
文献类型：
--
作者：
Denninger, JW;Schelvis, JPM;Marletta, MA
酶溶性鸟苷酸环化酶 (sGC) 可将 GTP 转化为 cGMP，是信号剂一氧化氮 (NO) 的受体。 YC-1 是一种合成的苄基吲唑衍生物，已被证明能够以不依赖于 NO 的方式激活 sGC。一氧化碳 (CO) 本身可将 sGC 激活约 5 倍，在一氧化碳 (CO) 存在的情况下，YC-1 将 sCC 激活至与单独 NO 刺激相当的水平。我们使用动力学分析和共振拉曼光谱 (RR) 来研究 YC-1 和 CO 与鸟苷酸环化酶的相互作用。在 CO 和 200 mu M YC-1 存在的情况下，V-max/K-m (GTP) 增加 226 倍。虽然YC-1不会干扰杆状病毒/Sf9细胞表达的sGC的亚铁形式的RR谱，但它会诱导GO结合形式的Fe-CO伸缩频率从474 cm(-1)转变为492 cm(-1)。同样，YC-1 对分离的 sGC 血红素结合结构域亚铁 beta 1(1-385) 的 RR 谱没有影响，但将 CO-β 1(1-385) 的 nu(Fe-CO) 从 478 cm(-1) 移动到 491 cm(-1)，表明 YC-1 结合在 sGC 的血红素结合区域。此外，在 YC-1 存在的情况下，sGC 和 beta 1(1-385) 的 GO 结合形式位于具有咪唑特征的近端配体的 nu(Fe-CO) 与 nu(C-O) 相关曲线上，这表明在 YC-1 存在的情况下，组氨酸仍然是血红素近端配体。有趣的是，YC-1 不会将 nu(Fe-CO) 转变为 H105G(Im) 的 CO 结合形式，H105G(Im) 是 beta 1(1-385) 的咪唑拯救血红素配体突变体。这些数据与 CO 和 YC-1 与 sGC 血红素结合结构域的结合导致构象变化一致，从而导致催化周转增加和血红素袋静电环境的变化。
The enzyme-soluble guanylate cyclase (sGC), which converts GTP to cGMP, is a receptor for the signaling agent nitric oxide (NO). YC-1, a synthetic benzylindazole derivative, has been shown to activate sGC in an NO-independent fashion. In the presence of carbon monoxide (CO), which by itself activates sGC approximately 5-fold, YC-1 activates sCC to a level comparable to stimulation by NO alone. We have used kinetic analyses and resonance Raman spectroscopy (RR) to investigate the interaction of YC-1 and CO with guanylate cyclase. In the presence of CO and 200 mu M YC-1, the V-max/K-m (GTP) increases 226-fold. While YC-1 does not perturb the RR spectrum of the ferrous form of baculovirus/Sf9 cell expressed sGC, it induces a shift in the Fe-CO stretching frequency for the GO-bound form from 474 to 492 cm(-1). Similarly, YC-1 has no effect on the RR spectrum of ferrous beta 1(1-385), the isolated sGC heme-binding domain, but shifts the nu(Fe-CO) of CO-beta 1(1-385) from 478 to 491 cm(-1), indicating that YC-1 binds in heme-binding region of sGC. In addition, the GO-bound forms of sGC and beta 1(1-385) in the presence of YC-1 lie on the nu(Fe-CO) vs nu(C-O) correlation curve for proximal ligands with imidazole character, which suggests that histidine remains the heme proximal ligand in the presence of YC-1. Interestingly, YC-1 does not shift nu(Fe-CO) for the CO-bound form of H105G(Im), the imidazole-rescued heme ligand mutant of beta 1(1-385). The data are consistent with binding of CO and YC-1 to the sGC hemebinding domain leading to conformational changes that give rise to an increase in catalytic turnover and a change in the electrostatic environment of the heme pocket.