COMPARISON OF THE FRAGMENTATION PRODUCED BY FAST ATOM BOMBARDMENT AND PHOTODISSOCIATION OF PEPTIDES
COMPARISON OF THE FRAGMENTATION PRODUCED BY FAST ATOM BOMBARDMENT AND PHOTODISSOCIATION OF PEPTIDES
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DOI：
10.1021/ja00205a006
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发表时间：
1989-11-08
影响因子：
15
通讯作者：
MCIVER, RT
中科院分区：
文献类型：
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作者：
LEBRILLA, CB;WANG, DTS;MCIVER, RT
激光光解具有许多特性，使其成为质谱法测定肽序列中碰撞诱导解离（CID）的一种有吸引力的替代方法。在本文中，我们报道了两种四肽（缬氨酸 - 丙氨酸 - 丙氨酸 - 苯丙氨酸和蛋氨酸 - 精氨酸 - 苯丙氨酸 - 丙氨酸）以及一种环状肽短杆菌肽S在193nm处的光解。实验是使用外置离子源傅里叶变换质谱仪（FTMS）和准分子激光器进行的。离子通过粒子束轰击产生，并被转移到FTMS分析器池中被捕获。当离子被捕获在分析器池中时，用准分子激光器发出的脉冲紫外光照射它们。在193nm处光解效率非常高。仅需一个激光脉冲就能使约60%的母离子裂解。裂解主要导致肽键断裂，并产生易于解读的质谱。含有高质子亲和力氨基酸（如脯氨酸）的残基会产生大量的碎片离子。这表明肽光解的机制主要由热力学因素控制，而不是由光化学因素（如链中各种氨基酸的摩尔吸光系数）控制。
Laser photodissociation has many features that make it an attractive alternative to collision-induced dissociation (CID) for sequencing peptides by mass spectrometry. In this paper we report on the photodissociation at 193 nm for two tetrapeptides (Val-Ala-Ala-Phe and Met-Arg-Phe-Ala) and a cyclic peptide, gramicidin S. The experiments are performed by using an external ion source Fourier transform mass spectrometer (FTMS) and an excimer laser. Ions are generated by particle beam bombardment and are transferred to an FTMS analyzer cell where they are trapped. While trapped in the analyzer cell, the ions are irradiated with pulsed UV light from an excimer laser. Photodissociation is very efficient at 193 nm. Only a single laser pulse is required to fragment about 60% of the parent ions. Fragmentation results mainly in cleavage of the peptide bonds and produces easily interpretable mass spectra. Abundant fragment ions are produced by residues that contain high proton affinity amino acids such as proline. This indicates that the mechanism of peptide photodissociation is controlled primarily by thermodynamic factors rather than photochemical factors such as the molar absorption coefficient of the various amino acids in the chain.