Structural studies of cytochrome b5: complete sequence-specific resonance assignments for the trypsin-solubilized microsomal ferrocytochrome b5 obtained from pig and calf.
Structural studies of cytochrome b5: complete sequence-specific resonance assignments for the trypsin-solubilized microsomal ferrocytochrome b5 obtained from pig and calf.
复制标题
细胞色素 b5 的结构研究：从猪和牛身上获得的胰蛋白酶溶解的微粒体铁细胞色素 b5 的完整序列特异性共振归属。
DOI：
10.1021/bi00457a025
复制
发表时间：
1990
期刊：
影响因子：
2.9
通讯作者：
Lipka,JJ
中科院分区：
文献类型：
--
作者：
Guiles,RD;Altman,J;Kuntz,ID;Waskell,L;Lipka,JJ
药物化学系、麻醉系和肝脏中心，加州大学，弗朗西斯科，加州94143，以及麻醉科，退伍军人管理局医疗中心，弗朗西斯科，加州94121接收日期：1989年6月14日;修订版手册接收日期：1989年10月2日摘要：我们报告了从小牛肝脏中获得的胰蛋白酶溶解的微粒体铁细胞色素b5的完整序列特异性质子共振归属。此外，还报道了猪细胞色素b5的主链氨基酸质子（即，C、C1和酰胺质子）的序列特异性共振归属。通过使用COSY和HOHAHA峰坐标作为输入的自动化程序，快速完成了大多数主链共振的分配。长侧链氨基酸自旋系统的鉴定是通过长程相干转移实验（HOHAHA）来实现的。共振重叠的问题得到解决，通过检查兔，猪，和小牛蛋白质的二维500 MHz NMR光谱之间的差异，并通过检查温度依赖性变化的酰胺质子共振。计算的芳环电流位移质子的X-射线晶体结构表明是接近芳香族残基被发现是有用的，在确证的分配，特别是那些由于大位移诱导的血红素。NOESY交叉峰的归属，大大促进了使用一个完整的弛豫矩阵分析的基础上的晶体结构的强度预测。这些结果表明，单晶X射线结构closely类似的解决方案的结构，虽然有证据表明，解决方案的结构有一个更动态的字符。（β细胞色素b是一种低自旋电子转移血红素蛋白，其执行多种重要的生理功能[综述参见马修斯和Czerwinski（1976）]。它以膜结合和水溶性形式存在。膜结合形式具有将蛋白质锚定到脂质双层的另外的疏水性α-螺旋结构域。存在两种类似的膜结合形式（MW约16 K）：一种定位于内质网，而另一种在线粒体膜中发现（Strittmatter & Velick，1956; Lederer等人，1983年）。在内质网中，细胞色素b为脂肪酸去饱和和胆固醇生物合成（Oshino，1978）以及通过细胞色素P-450氧化某些底物（Canova-Davis & Waskell，1984; Pompon & Coon，1984; Vatsis et al.，1982年; Noshiro等人，1979年）。细胞色素b在细胞色素P-450系统中的作用似乎是提供某些底物氧化所需的两个电子中的第二个（Hildebrandt & Estabrook，1971）。线粒体形式的功能是未知的。该蛋白质的可溶形式（MW约10 K）天然存在于红细胞中，其功能是还原高铁血红蛋白（Hegesh等人，1986年）。在这里描述的研究中，我们使用了一种可溶性形式，
Department of Pharmaceutical Chemistry, Department of Anesthesia, and Liver Center, University of California, San Francisco, California 94143, and Anesthesiology Service, Veterans Administration Medical Center, San Francisco, California 94121 Received June 14, 1989; Revised Manuscript Received October 2, 1989 abstract: We report completesequence-specific proton resonance assignments for the trypsin-solubilized microsomal ferrocytochrome b5 obtained fromcalf liver. In addition, sequence-specific resonance assignments for the main-chain amino acid protons (ie, C, C^, and amide protons) are also reported for the porcine cytochrome b5. Assignment of the majority of the main-chain resonances was rapidly accomplished by automated procedures that used COSY and HOHAHA peak coordinates as input. Long side chainamino acid spin system identification was facilitated by long-range coherence-transfer experiments (HOHAHA). Problems with resonance overlap were resolved by examining differences between the two-dimensional 500-MHz NMR spectra of rabbit, pig, and calf proteins and by examining the temperature-dependent variation of amide proton resonances. Calculations of the aromatic ring-current shifts for protons that the X-ray crystal structure indicated were proximal to aromatic residues were found to be useful in corroborating assignments, especially those due to the large shifts induced by the heme. Assignment of NOESY cross peaks was greatly facilitated by a prediction of intensities using a complete relaxation matrix analysis based on the crystal structure. These results suggest that the single-crystal X-ray structureclosely resembles that of the solution structure although there is evidence that the solution structure has a more dynamic character.(/ytochrome bs is a low-spin electron-transfer hemoprotein that carries out a variety of important physiological functions [for a review, see Mathews and Czerwinski (1976)]. It exists in a membrane-bound and water-soluble form. The mem-brane-bound form has an additional hydrophobic a-helical domain that anchors the protein to the lipid bilayer. Two similar membrane-bound forms (MW approximately 16K) exist: one is localized to the endoplasmic reticulum while the other is found in the mitochondrial membrane (Strittmatter & Velick, 1956; Lederer et al., 1983). In the endoplasmic reticulum cytochrome bs provides reducing equivalents for fatty acid desaturation and cholesterol biosynthesis (Oshino, 1978) and for the oxidation of certain substratesby cytochrome P-450 (Canova-Davis & Waskell, 1984; Pompon & Coon, 1984; Vatsis et al., 1982; Kuwahara & Omura, 1980; Noshiro et al., 1979). The role of cytochrome bs in the cytochrome P-450 system appears to be in providing thesecond of two electrons required for the oxidation of certain substrates (Hildebrandt & Estabrook, 1971). The function of the mitochondrial form is unknown. The soluble form of the protein (MW approximately 10K) occurs naturally in erythrocytes where it functions to reduce methemoglobin (Hegesh et al., 1986). In the studies described here, we utilized a soluble form
登录
查看更多内容
电子从细胞色素 b5 转移到铁和铜复合物。
影响因子：
2.9
作者：
Reid,LS;Gray,HB;Dalvit,C;Wright,PE;Saltman,P
通讯作者：
Saltman,P
生物电子转移速率对放热的依赖性。
DOI：
--
发表时间：
1985
期刊：
影响因子：
--
作者：
G. Mclendon;John R. Miller
通讯作者：
John R. Miller
影响因子：
--
作者：
Basus,VJ
通讯作者：
Basus,VJ
DOI：
10.1016/0005-2795(76)90192-6
发表时间：
1976-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
KELLER, R;GROUDINSKY, O;WUTHRICH, K
通讯作者：
WUTHRICH, K
影响因子：
2.2
作者：
C. Eads;I. Kuntz
通讯作者：
I. Kuntz