Observation of the terminal methyl group in fatty acids of the linolenic series by a new 1H NMR pulse sequence providing spectral editing and solvent suppression. Application to excised frog muscle and rat brain.
Observation of the terminal methyl group in fatty acids of the linolenic series by a new 1H NMR pulse sequence providing spectral editing and solvent suppression. Application to excised frog muscle and rat brain.
复制标题
通过提供光谱编辑和溶剂抑制的新 1H NMR 脉冲序列观察亚麻酸系列脂肪酸中的末端甲基。
DOI：
10.1021/bi00359a038
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发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Markley,JL
中科院分区：
文献类型：
--
作者：
Arús,C;Westler,WM;Bárány,M;Markley,JL
伊利诺伊大学医学院生物化学系，伊利诺伊大学，芝加哥，伊利诺伊60612，和威斯康星大学农业和生命科学学院生物化学系，威斯康星大学麦迪逊，麦迪逊，威斯康星州53706；修订手稿，1986年2月3日收到摘要：描述了一种新的*H核磁共振脉冲序列，其结合了水抑制和对来自耦合自旋系统的信号的选择性观察。该脉冲序列易于设置并补偿生物样品中的脉冲宽度不均匀。水信号的抑制是通过使水自旋返回到其平衡位置的脉冲来实现的；光谱编辑是基于自旋回波谱中存在的J调制，并通过在感兴趣的自旋系统的一个共振处的相干去耦合来抑制它。该脉冲序列是为组织的核磁共振波谱而设计的，在470 MHz的频率下对青蛙肌肉和大鼠的大脑进行了测试。用咖啡因处理的青蛙缝纫肌的酒精质子位置，选择性地观察其乳酸甲酯共振。在ITS-L亚甲基位置，选择性地观察到亚麻酸和亚麻酸系列的其他脂肪酸(-3位的第一个双键)的末端甲基信号。对大鼠脑的核磁共振谱进行编辑，以揭示亚麻酸系列或所有其他脂肪酸的末端甲基。结果表明，亚麻酸系列脂肪酸的末端甲基(主要是二十二碳六烯酸，22：6)比所有其他脂肪酸具有更高的流动性。
Department of Biological Chemistry, College of Medicine, University of Illinois, Chicago, Illinois 60612, and Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin—Madison, Madison, Wisconsin 53706 Received September 16, 1985; Revised Manuscript Received February 3, 1986 abstract: A new* H NMR pulse sequence is described that combines water suppression with the selective observation of signals from coupled spin systems. The pulse sequence is easy to set up and compensates for pulse width inhomogeneity inthe biological sample. Suppression of the water signal is achieved by pulses that return the water spins to their equilibrium position; spectral editing is based on the J modulation present in spin-echo spectra and its inhibition by coherent decoupling at one of the resonances of the spin system of interest. The pulse sequence, which was designed for* H NMR spectroscopy of tissue, was tested at 470 MHz on excised frog muscle and rat brain. The lactate methyl resonance of caffeine-treated frog sartorius muscle was observed selectively by irradiation at the position of its alcoholic proton. The terminal methyl signal of linolenic acid, along with other fatty acids of the linolenic series (first double bond in the-3 position), was observed selectively by irradiation at the position of its-l methylene group. NMR spectra of rat brain were edited to reveal the terminal methyl of either linolenic series or all other fatty acids. The results suggest that the terminal methyl groups of fatty acids of the linolenic series (mostly docosahexaenoic acid, 22: 6) have higher mobility than those of all other fatty acids.