Carbon edge XANES spectroscopy of amino acids and peptides
Carbon edge XANES spectroscopy of amino acids and peptides
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DOI：
10.1016/s0368-2048(97)00032-7
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发表时间：
1997-04-01
影响因子：
1.9
通讯作者：
Kirz, J
中科院分区：
文献类型：
--
作者：
Boese, J;Osanna, A;Kirz, J
首次研究了氨基酸和小肽的碳边缘X射线吸收近边缘结构（XANES）。由于样品的热敏感性，蒸发样品的气相光谱分析很困难。因此，它们以固体形式作为薄膜进行分析。定量吸收测量要求被照射的样品区域具有均匀的厚度。为此，使用了特殊的样品制备技术，并使用石溪扫描透射 X 射线显微镜的小光斑尺寸获取光谱，该显微镜在布鲁克海文国家实验室的国家同步加速器光源下运行。测量并比较了六种氨基酸单体、四种二肽和一种三肽的碳K边XANES光谱。结果表明，肽光谱可以解释为它们所组成的单体的光谱之和。这表明肽键对光谱只有微弱的影响。如果这在一般情况下是正确的，那么应该可以从组成氨基酸的光谱预测蛋白质的 XANES 光谱。这可用于使用 X 射线显微镜进行蛋白质特异性成像。 (C) 1997 Elsevier Science B.V.
Carbon edge X-ray absorption near-edge structures (XANES) of amino acids and small peptides have been investigated for the first time. Because of the heat sensitivity of the samples, gas phase spectroscopy of evaporated samples is difficult. Therefore they were analyzed in solid form as thin films. Quantitative absorption measurements require the region of the sample which is illuminated to be of uniform thickness. For this reason a special sample preparation technique was used, and the spectra were taken using the small spot size of the Stony Brook scanning transmission X-ray microscope, which is operated at the National Synchrotron Light Source at Brookhaven National Laboratory. Carbon K-edge XANES spectra of six amino acid monomers, four dipeptides and one tripeptide were measured and compared. The results show that the peptide spectra can be explained as a sum of the spectra of the monomers they consist of. This indicates that the peptide bond has only a weak effect on the spectra. If this is true in general, it should be possible to predict XANES spectra of proteins from the spectra of the constituent amino acids. This could be used in protein specific imaging using X-ray microscopes. (C) 1997 Elsevier Science B.V.