MS/MS Simplification by 355 nm Ultraviolet Photodissociation of Chromophore-Derivatized Peptides in a Quadrupole Ion Trap
作者:Jeffrey J. Wilson、Jennifer S. Brodbelt
DOI:10.1021/ac071241t
日期:2007.10.1
Ultraviolet photodissociation (UVPD) of chromophore-modified peptides enhances the capabilities for de novo sequencing in a quadrupole ion trap mass spectrometer. Attachment of UV chromophores allows efficient photoactivation of not only the precursor ions but also any fragments that retain the chromophore functionality. For doubly protonated peptides, UVPD leads to a vast reduction in MS/MS complexity
Infrared Multiphoton Dissociation for Enhanced de Novo Sequence Interpretation of N-Terminal Sulfonated Peptides in a Quadrupole Ion Trap
作者:Jeffrey J. Wilson、Jennifer S. Brodbelt
DOI:10.1021/ac060760d
日期:2006.10.1
Infrared multiphoton dissociation (IRMPD) of N-terminal sulfonated peptides improves de novo sequencing capabilities in a quadrupole ion trap mass spectrometer. Not only does IRMPD promote highly efficient dissociation of the N-terminal sulfonated peptides but also the entire series of y ions down to the y1 fragment may be detected due to alleviation of the low-mass cutoff problem associated with conventional collisional activated dissociation (CAD) methods in a quadrupole ion trap. Commercial de novo sequencing software was applied for the interpretation of CAD and IRMPD MS/MS spectra collected for seven unmodified peptides and the corresponding N-terminal sulfonated species. In most cases, the additional information obtained by N-terminal sulfonation in combination with IRMPD provided significant improvements in sequence identification. The software sequence tag results were combined with a commercial database searching algorithm to interpret sequence information of a tryptic digest on α-casein s1. Energy-variable CAD studies confirmed a 30−40% reduction in the critical energies of the N-terminal sulfonated peptides relative to unmodified peptides. This reduction in dissociation energy facilitates IRMPD in a quadrupole ion trap.
N 端磺化肽的红外多光子解离 (IRMPD) 提高了四极离子阱质谱仪中的从头测序能力。 IRMPD 不仅可以促进 N 端磺化肽的高效解离,而且由于缓解了与传统碰撞激活解离 (CAD) 相关的低质量截断问题,因此可以检测到 y1 片段的整个 y 离子系列四极离子阱中的方法。应用商业从头测序软件来解释为七种未修饰的肽和相应的 N 末端磺化物质收集的 CAD 和 IRMPD MS/MS 谱。在大多数情况下,通过 N 端磺化与 IRMPD 结合获得的附加信息显着改善了序列识别。软件序列标签结果与商业数据库搜索算法相结合,以解释 α-酪蛋白 s1 胰蛋白酶消化的序列信息。能量可变 CAD 研究证实,相对于未修饰的肽,N 端磺化肽的临界能量降低了 30−40%。解离能的降低有利于四极离子阱中的 IRMPD。
Real-time reaction monitoring by continuous-introduction ion-spray tandem mass spectrometry
作者:Edgar D. Lee、Wolfgang Mueck、Jack D. Henion、Thomas R. Covey
DOI:10.1021/ja00195a012
日期:1989.6
for real-time measurement of reactions. The reaction medium, reactants, and products were transferred to the ion source of the mass spectrometer from the reaction vessel in less than 1 s. A variety of model reactions have been investigated to demonstrate the feasibility acd potential for continuous-introduction ion-spray massspectrometry for real-time reactionmonitoring. The half-life for the solvolysis
The ornithine effect in peptide cation dissociation
作者:William M. McGee、Scott A. McLuckey
DOI:10.1002/jms.3233
日期:2013.7
decrease of the gas phase protonaffinity of the residue, thereby increasing the mobility of the ionizingproton. This alteration allows the nucleophilic amine to facilitate a neighboring group reaction to induce a cleavage of the adjacent amide bond. The selective cleavage at the ornithine residue is proposed to result from the highly favorable generation of a six‐membered lactam ring. The ornithine effect