Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
J Mass Spectrom. 2010 Jul;45(7):806-14. doi: 10.1002/jms.1773.
Time-resolved photodissociation (PD) patterns of singly protonated peptides with arginine at the C-terminus (C-arg peptide ions) have been used to classify the dissociation channels into two categories, i.e. high-energy channels generating v, w and x and low-energy ones generating b, y and z. x + 1 formed by C(alpha)-CO cleavage seems to be the intermediate ion in high-energy channels just as a + 1 is for N-arg peptide ions. Difference in time-resolved pattern indicates that the two sets of channels, high- and low-energy ones, are not in direct competition. Noncompetitive dissociation is also indicated by the observation of anomalous effect of matrix used in matrix-assisted laser desorption ionization, a cooler matrix generating more high-energy product ions both in spontaneous dissociation and in PD. Results from detailed investigation suggest that the two sets of channels start from two (or more) different conformations.
时间分辨光解 (PD) 模式的单质子化肽与精氨酸在 C 末端 (C-精氨酸肽离子) 已被用来将解离通道分为两类，即产生 v、w 和 x 的高能通道和产生 b、y 和 z 的低能通道。似乎由 C(alpha)-CO 裂解形成的 x + 1 是高能通道中的中间离子，就像 N-精氨酸肽离子中的 a + 1 一样。时间分辨模式的差异表明，两组通道，高能和低能通道，不是直接竞争的。非竞争解离也由基质辅助激光解吸电离中所用基质的异常效应所表明，冷却基质在自发解离和 PD 中都产生更多的高能产物离子。详细研究的结果表明，两组通道起始于两种（或更多）不同的构象。
