Department of Chemistry, The American University in Cairo, New Cairo, Egypt.
J Am Soc Mass Spectrom. 2013 Jan;24(1):38-48. doi: 10.1007/s13361-012-0511-y. Epub 2012 Dec 13.
The fragmentations of AA + M complexes, where AA = Phe, Tyr, Trp, or His, and M is a monovalent metal (Li, Na, or Ag), have been exhaustively studied through collision-induced dissociation (CID) and through deuterium labeling. Dissociations of the Li- and Ag-containing complexes gave a large number of fragment ions; by contrast, the sodium/amino acid complexes have lower binding energies, and dissociation resulted in much simpler spectra, with loss of the entire ligand dominating. Unambiguous assignments of these fragment ions were made and formation mechanisms are proposed. Of particular interest are fragmentations in which the charge was retained on the organic fragment and the metal was lost, either as a metal hydride (AgH) or hydroxide (LiOH) or as the silver atom (Ag(•)).
已通过碰撞诱导解离（CID）和氘标记对 AA + M 配合物的碎片（其中 AA = Phe、Tyr、Trp 或 His，M 是单价金属（Li、Na 或 Ag））进行了详尽的研究。含有 Li 和 Ag 的配合物的解离产生了大量的碎片离子；相比之下，含钠/氨基酸的配合物具有较低的结合能，解离导致更简单的光谱，整个配体的丢失占主导地位。对这些碎片离子进行了明确的归属，并提出了形成机制。特别有趣的是，在这些碎片中，电荷保留在有机片段上，金属以金属氢化物 (AgH) 或氢氧化物 (LiOH) 的形式或作为银原子 (Ag(•)) 丢失。
