Department of Chemical Engineering, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA.
J Am Soc Mass Spectrom. 2011 Jan;22(1):49-56. doi: 10.1007/s13361-010-0016-5. Epub 2011 Jan 21.
The fragmentation patterns obtained by ultraviolet photodissociation (UVPD) and collision-induced dissociation (CID) in a quadrupole ion trap mass spectrometer were compared for peptides modified at their C-termini and at acidic amino acids. Attachment of Alexa Fluor 350 or 7-amino-4-methyl-coumarin chromophores at the C-terminal and acidic residues enhances the UV absorptivity of the peptides and all fragment ions that retain the chromophore, such as the y ions that contain the chromophore-modified C-terminus. Whereas CID results in the formation of the typical array of mainly y-type and a/b-type fragment ions, UVPD produces predominantly a/b-type ions with greatly reduced abundances of y ions. Immonium ions, mostly ones from aromatic or basic amino acids, are also observed in the low m/z range upon UVPD. UVPD of peptides containing two chromophore moieties (with one at the C-terminus and another at an acidic residue) results in even more efficient photodissociation at the expense of the annihilation of almost all diagnostic b and y ions containing the chromophore.
在四极离子阱质谱仪中，通过紫外光解（UVPD）和碰撞诱导解离（CID）获得的肽的碎片模式进行了比较，这些肽在 C 末端和酸性氨基酸处进行了修饰。在 C 末端和酸性残基处附加 Alexa Fluor 350 或 7-氨基-4-甲基香豆素发色团可增强肽和保留发色团的所有片段离子的紫外吸收率，例如含有发色团修饰 C 末端的 y 离子。虽然 CID 导致形成典型的主要 y 型和 a/b 型片段离子的阵列，但 UVPD 主要产生 a/b 型离子，y 离子的丰度大大降低。在 UVPD 时，还在低 m/z 范围内观察到主要来自芳香族或碱性氨基酸的亚铵离子。含有两个发色团部分的肽（一个在 C 末端，另一个在酸性残基处）的 UVPD 以牺牲几乎所有含有发色团的诊断 b 和 y 离子的湮灭为代价，导致更有效的光解。
