Chemistry Department and GIGA-R, Mass Spectrometry Laboratory, University of Liege, Liege, Belgium.
J Am Soc Mass Spectrom. 2013 Feb;24(2):297-300. doi: 10.1007/s13361-012-0523-7. Epub 2013 Jan 11.
MALDI in-source decay (ISD) has been used for top-down sequencing of proteins. The use of the matrix 1,5-diaminonapthalene (1,5-DAN) gave abundant w ions, which are formed from the unimolecular dissociation of z• radical fragments via α cleavage reaction and thus help identify which of the isobaric amino acids, Leu or Ile, is present. The high abundance of w ions in MALDI-ISD with 1,5-DAN results from the low collision rate in the MALDI plume. MALDI-ISD with 1,5-DAN appears to be an useful method for the top-down sequencing of proteins, including discrimination of Leu and Ile near the C-terminal end.
基质辅助激光解吸电离源内裂解（MALDI-ISD）已被用于蛋白质的从头测序。使用基质 1,5-二氨基萘（1,5-DAN）可产生丰富的 w 离子，这些离子是通过α断裂反应从 z•自由基碎片的单分子解离形成的，因此有助于确定存在的是等摩尔的氨基酸亮氨酸或异亮氨酸。在 MALDI 羽流中低碰撞速率导致用 1,5-DAN 进行 MALDI-ISD 时，w 离子的丰度很高。对于包括靠近 C 末端的亮氨酸和异亮氨酸的区分在内的蛋白质从头测序，MALDI-ISD 与 1,5-DAN 结合似乎是一种有用的方法。
