Setner Bartosz, Rudowska Magdalena, Klem Ewelina, Cebrat Marek, Szewczuk Zbigniew
Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383, Wrocław, Poland.
J Mass Spectrom. 2014 Oct;49(10):995-1001. doi: 10.1002/jms.3410.
Improving the sensitivity of detection and fragmentation of peptides to provide reliable sequencing of peptides is an important goal of mass spectrometric analysis. Peptides derivatized by bicyclic quaternary ammonium ionization tags: 1-azabicyclo[2.2.2]octane (ABCO) or 1,4-diazabicyclo[2.2.2]octane (DABCO), are characterized by an increased detection sensitivity in electrospray ionization mass spectrometry (ESI-MS) and longer retention times on the reverse-phase (RP) chromatography columns. The improvement of the detection limit was observed even for peptides dissolved in 10 mM NaCl. Collision-induced dissociation tandem mass spectrometry of quaternary ammonium salts derivatives of peptides showed dominant a- and b-type ions, allowing facile sequencing of peptides. The bicyclic ionization tags are stable in collision-induced dissociation experiments, and the resulted fragmentation pattern is not significantly influenced by either acidic or basic amino acid residues in the peptide sequence. Obtained results indicate the general usefulness of the bicyclic quaternary ammonium ionization tags for ESI-MS/MS sequencing of peptides.
提高肽段检测和碎片化的灵敏度以实现可靠的肽段测序是质谱分析的一个重要目标。通过双环季铵离子化标签（1-氮杂双环[2.2.2]辛烷（ABCO）或1,4-二氮杂双环[2.2.2]辛烷（DABCO））衍生化的肽段，其特点是在电喷雾电离质谱（ESI-MS）中检测灵敏度提高，并且在反相（RP）色谱柱上的保留时间延长。即使对于溶解在10 mM NaCl中的肽段，也观察到了检测限的改善。肽段季铵盐衍生物的碰撞诱导解离串联质谱显示出主要的a型和b型离子，便于肽段测序。双环离子化标签在碰撞诱导解离实验中稳定，并且所得的碎片化模式不受肽序列中酸性或碱性氨基酸残基的显著影响。获得的结果表明双环季铵离子化标签在肽段ESI-MS/MS测序中的普遍实用性。
