Electron-nuclear coupling in nitrosyl heme proteins and in nitrosyl ferrous and oxy cobaltous tetraphenylporphyrin complexes.
Electron-nuclear coupling in nitrosyl heme proteins and in nitrosyl ferrous and oxy cobaltous tetraphenylporphyrin complexes.
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亚硝酰血红素蛋白以及亚硝酰亚铁和氧钴四苯基卟啉复合物中的电子-核耦合。
DOI：
10.1021/bi00398a057
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发表时间：
1987
期刊：
影响因子：
2.9
通讯作者：
Peisach,J
中科院分区：
文献类型：
--
作者：
Magliozzo,RS;McCracken,J;Peisach,J
阿尔伯特·爱因斯坦医学院分子药理学系，布朗克斯，纽约10461摘要：利用电子自旋回波包络调制（ESEEM）光谱研究了以下等电子5='/2配合物的电子-核相互作用：NO-Fen (TPP)（TPP= et-raphenylporphyrin）有和没有轴向氮基，R和T态的亚硝基血红蛋白，02-Con （TPP）有和没有轴向基。只有卟啉吡咯氮参与6-配位亚硝基芬（TPP）配合物、亚硝基血红蛋白（r -态）以及a链和β链亚硝基配合物的ESEEM。五坐标配合物NO-Fen （TPP）中的吡咯氮与不成对自旋的耦合太弱，因此不参与ESEEM。部分饱和的t态亚硝基血红蛋白不表现出6配位亚硝基血红蛋白的回声包膜调节特征，这证实了咪唑与血红素铁的近端键被破坏。利用14n和15n标记配体和卟啉对6-坐标02-Con (TPP)(L)配合物（L=含氮碱）进行研究，可以详细分析吡咯和轴向氮的偶联参数。吡咯- 14N耦合频率与NO-FeII （TPP）相似(L)。通过模拟一系列02-Con (TPP)(L)配合物（L=吡啶、4-吡啶、4-氰吡啶、4-羧基吡啶和1-、2-和4-甲基咪唑）的ESEEM光谱，计算出轴向结合氮的费米接触耦合，表明与弱碱的超精细相互作用倾向于更强。金属卟啉复合物的磁共振性质通常可以为血红素蛋白的生物化学提供见解。对金属卟啉中未配对电子自旋和附近原子核之间相互作用的理解，使光谱学家能够解决金属卟啉所在的蛋白质对这些相互作用的影响，并将假基性质与该蛋白质的三级和四级结构联系起来。电子顺磁共振波谱已广泛应用于高、低自旋铁血红素蛋白（Blumberg et al., 1968; Peisach et al., 1971; Chevion et al., 1977; Hollenberg et al., 1980; Palmer, 1985）和亚铁亚硝基血红素蛋白（Kon, 1968; Yonetani et al., 1972; Chevion et al., 1977； Hille等）的研究。, 1979;Morse & Chan, 1980；Hori et al., 1981；LoBrutto et al., 1983)。总的来说，这些研究已经解决了血红素铁的轴向配体的身份。EPR1和ENDOR技术在f中的应用这项工作得到了美国国立卫生研究院拨款HL-13399和RR-02583的支持。血红蛋白变构的化学性质为亚硝基血红蛋白a的a亚基中近端咪唑Fe-N键以低亲和形式或T态被破坏提供了证据（Hóhn et al., 1983）。亚硝基血红蛋白的大量证据表明这种键的稳定性（Szabo & Perutz, 1976； Nagai等人，1980；Ascenzi等人，1981）。
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461 Received April 29, 1987; Revised Manuscript Received July 2, 1987 abstract: Electron spin echo envelope modulation (ESEEM) spectroscopy has been used to study elec-tron-nuclear interactions in the following isoelectronic 5='/2 complexes: NO-Fen (TPP)(TPP= tet-raphenylporphyrin) with and without axial nitrogenous base, nitrosylhemoglobin in R and T states, and 02-Con (TPP) with and without axial base. Only the porphyrin pyrrole nitrogens contribute to the ESEEM of the 6-coordinate nitrosyl Fen (TPP) complexes, nitrosylhemoglobin (R-state), and the nitrosyl complexes of a and ß chains. Pyrrole nitrogens in the 5-coordinate complex NO-Fen (TPP) are coupled too weakly to unpaired spin and therefore donot contribute to the ESEEM. A partially saturated T-state nitrosyl-hemoglobin does not exhibit echo envelope modulations characteristic of 6-coordinate nitrosyl species, which confirms that the proximal imidazole bond to heme iron is disrupted. Study of 6-coordinate 02-Con (TPP)(L) complexes (L= nitrogenous base) using 14N-and 15N-labeled ligands and porphyrins enabled a detailed analysis of coupling parameters for both pyrrole and axial nitrogens. The pyrrole 14N coupling frequencies are similar to those in NO-FeII (TPP)(L). The Fermi contact couplings for axially bound nitrogen, calculated from simulation of ESEEM spectra for a series of 02-Con (TPP)(L) complexes (L= pyridine, 4-picoline, 4-cyanopyridine, 4-carboxypyridine, and 1-, 2-, and 4-methylimidazole) illustrate a trend toward stronger hyperfine interactions with weaker bases. e magnetic resonance properties of metalloporphyrin complexes can often provide insight into the biochemistry of heme proteins. An understanding of the interactions between unpaired electron spin and nearby nuclei in metalloporphyrins enables the spectroscopist to address the effects on these interactions imposed by the protein in which the metalloporphyrin resides and torelate the prosthetic group properties to the tertiary and quaternary structure of that protein. Electron paramagnetic resonance spectroscopy has been extensively used in studies of high-and low-spin ferric heme proteins (Blumberg et al., 1968; Peisach et al., 1971; Chevion et al., 1977; Hollenberg et al., 1980; Palmer, 1985) and ferrous nitrosyl heme proteins (Kon, 1968; Yonetani et al., 1972; Chevion et al., 1977; Hille et a!., 1979; Morse & Chan, 1980; Hori et al., 1981; LoBrutto et al., 1983). These studies, in general, have addressed the identity of axial ligands to heme iron. An application of EPR1 and ENDOR techniques to the f This work was supported by Grants HL-13399 and RR-02583 from the National Institutes of Health. chemistry of allosterism in hemoglobin has provided evidence for the disruption of the proximal imidazole Fe-N bond in the a subunits of nitrosylhemoglobin A in the low-affinity form, or T state (Hóhn et al., 1983). The lability of this bond is suggested by a body of evidence for nitrosylhemoglobins (Szabo & Perutz, 1976; Nagai et al., 1980; Ascenzi et al., 1981).
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高铁肌红蛋白中血红素铁的水协调。
DOI：
--
发表时间：
1984
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Peisach,J;Mims,WB;Davis,JL
通讯作者：
Davis,JL
亚硝基血红蛋白中伴随 R→T 转变的 14N 超精细相互作用观察到的变化的起源
DOI：
10.1073/pnas.76.10.4842
发表时间：
1979
影响因子：
11.1
作者：
S. K. Mun;Jane C. Chang;T. P. Das
通讯作者：
T. P. Das
DOI：
--
发表时间：
1977
期刊：
影响因子：
--
作者：
Y. Hsieh;G. V. Rubenacker;C. Cheng;T. L. Brown
通讯作者：
T. L. Brown
亚硝酰血红蛋白中六配位和五配位血红素之间的平衡：电子自旋共振谱的解释。
影响因子：
2.9
作者：
A. Szabo;M. Perutz
通讯作者：
M. Perutz
使用自旋回波法测量 EPR 中的线性电场效应
影响因子：
1.6
作者：
W. Mims
通讯作者：
W. Mims