FTIR spectroscopy of cysteine as a ready-to-use method for the investigation of plasma-induced chemical modifications of macromolecules
FTIR spectroscopy of cysteine as a ready-to-use method for the investigation of plasma-induced chemical modifications of macromolecules
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DOI：
10.1088/0022-3727/49/8/084004
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发表时间：
2016-03-02
影响因子：
3.4
通讯作者：
Lackmann, Jan-Wilm
中科院分区：
文献类型：
--
作者：
Kogelheide, Friederike;Kartaschew, Konstantin;Lackmann, Jan-Wilm
建立了一种利用傅里叶变换红外光谱(FTIR)分析半胱氨酸的快速筛选方法，用于研究等离子体诱导的化学修饰。半胱氨酸是蛋白质中的一种关键氨基酸，因为它存在一个硫醇基团，它提供了形成二硫键的可能性，从而提供了独特的结构特征。半胱氨酸的化学组成使其成为研究等离子体诱导的三个官能团-氨基、羧基和硫基-的修饰的理想模型，这些官能团都在蛋白质中高度丰富。FTIR光谱存在于大多数物理实验室中，它提供了一种快速的方法来评估由于等离子体处理而引起的半胱氨酸底物的化学成分的变化，并比较不同的处理条件或等离子体源。用FTIR光谱仪观察到经介质阻挡放电(DBD)处理的半胱氨酸样品与未处理的对照样品相比，半胱氨酸样品的指纹图谱发生了显著变化。在DBD处理过程中，硫醇信号的消失和氧化硫氮物种的谱带同时增加，表明半胱氨酸的硫醇基团被活性氧和氮物种修饰。此外，还可以观察到其他等离子体诱导的修饰，如氨基和羰基的变化。互补质谱学测量证实了这些结果。
A rapid screening method for the investigation of plasma-induced chemical modifications was developed by analyzing cysteine using Fourier Transform Infrared (FTIR) spectroscopy. Cysteine is a key amino acid in proteins due to the presence of a thiol group which provides unique structural features by offering the possibility to form disulfide bonds. Its chemical composition makes cysteine a well-suited model for the investigation of plasma-induced modifications at three functional groups-the amino, the carboxyl and the thiol group-all highly abundant in proteins. FTIR spectroscopy is present in most physical laboratories and offers a fast way to assess changes in the chemical composition of cysteine substrates due to plasma treatment and to compare different treatment conditions or plasma sources with each other. Significant changes in the fingerprint spectra of cysteine samples treated with a dielectric barrier discharge (DBD) compared to untreated controls were observed using a FTIR spectrometer. The loss of the thiol signal and the simultaneous increase of bands originating from oxidized sulfur and nitrogen species indicate that the thiol group of cysteine is modified by reactive oxygen and nitrogen species during DBD treatment. Furthermore, other plasma-induced modifications, such as changes of the amino and carbonyl groups, could be observed. Complementary mass spectrometry measurements confirmed these results.