Identification of Nitric Oxide Synthase as a Thiolate-ligated Heme Protein Using Magnetic Circular Dichroism Spectroscopy
Identification of Nitric Oxide Synthase as a Thiolate-ligated Heme Protein Using Magnetic Circular Dichroism Spectroscopy
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使用磁圆二色光谱鉴定一氧化氮合酶为硫醇盐连接的血红素蛋白
DOI：
--
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发表时间：
1995
影响因子：
4.8
通讯作者：
J. Dawson
中科院分区：
文献类型：
--
作者：
M. Sono;D. Stuehr;M. Ikeda;J. Dawson
一氧化氮（NO）是一种重要的生物分子，具有多种生理功能。它是在几种不同的组织中由L-Arg和O2合成的，使用NADPH作为电子供体，由一个家族的含血红素的催化自给自足的单加氧酶称为一氧化氮合酶（NOS）。最近，还原型NOS的CO复合物已被证明在450 nm附近表现出最大吸收，这是细胞色素P-450（P-450）的特征光谱特征。然而，NOS和P-450的氨基酸序列没有同源性。为了进一步探讨NOS活性中心血红素的配位结构和血红素的环境，我们采用了磁性圆二色性（MCD）和CD光谱在本研究。MCD光谱的几个衍生物的大鼠脑神经元NOS惊人的类似衍生物的细菌P-450-CAM和真菌氯过氧化物酶，两个已知的巯基连接血红素蛋白。鉴于MCD光谱的指纹识别能力已得到证实，这为内源性硫醇盐（半胱氨酸）与NOS的血红素铁的连接提供了令人信服的证据。此外，NOS（阳性）和P-450（阴性）的血红素相关Soret CD带，如P-450-CAM所示，几乎是镜像，而氯过氧化物酶则表现出完全不同的CD带形状。这表明NOS和P-450的活性位点可能具有一些共同的结构特征，但它们的血红素环境在某些方面（如疏水性或大小）存在显著差异。
Nitric oxide (NO) has recently been recognized as an important biomolecule playing diverse physiological roles. It is synthesized in several different tissues from L-Arg and O2, using NADPH as an electron donor, by a family of heme-containing catalytically self-sufficient monooxygenases known as nitric oxide synthases (NOS). Recently, the CO complex of reduced NOS has been shown to exhibit an absorption maximum near 450 nm, a characteristic spectral feature of cytochrome P-450 (P-450). Yet, the amino acid sequences of NOS and P-450 have no homology. To further probe the active site heme coordination structure and the heme environment of NOS, we have employed magnetic circular dichroism (MCD) and CD spectroscopy in the present study. MCD spectra of several derivatives of rat brain neuronal NOS strikingly resemble those of analogous derivatives of bacterial P-450-CAM and fungal chloroperoxidase, two known thiolate-ligated heme proteins. Given the proven fingerprinting capability of MCD spectroscopy, this provides convincing evidence for endogenous thiolate (cysteinate) ligation to the heme iron of NOS. Furthermore, the heme-related Soret CD bands of NOS (positive) and P-450s (negative), as represented by P-450-CAM, are almost mirror images, whereas chloroperoxidase exhibits totally different CD band shapes. This suggests that the active sites of NOS and P-450 may share some common structural features, but significant distinctions exist between their heme environments in certain aspects such as hydrophobicity or size.
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影响因子：
56.9
作者：
RAVICHANDRAN, KG;BODDUPALLI, SS;DEISENHOFER, J
通讯作者：
DEISENHOFER, J
大鼠神经元一氧化氮合酶的血红素和黄素结合域作为不同多肽的原核表达：将血红素结合近端硫醇配体鉴定为半胱氨酸-415。
影响因子：
2.9
作者：
McMillan,K;Masters,BS
通讯作者：
Masters,BS
DOI：
10.1016/0167-4838(83)90178-4
发表时间：
1983-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
ANDERSSON, LA;SONO, M;DAWSON, JH
通讯作者：
DAWSON, JH
影响因子：
2.9
作者：
K. White;M. Marletta
通讯作者：
K. White;M. Marletta
亚铁氯过氧化物酶与双氧、一氧化氮和烷基异氰化物复合物的制备和性质。
DOI：
--
发表时间：
1985
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Sono,M;Eble,KS;Dawson,JH;Hager,LP
通讯作者：
Hager,LP