New Approach for Pseudo-MS3 Analysis of Peptides and Proteins via MALDI In-Source Decay Using Radical Recombination with 1,5-Diaminonaphthalene
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- 作者：Daiki Asakawa ; Nicolas Smargiasso ; Edwin De Pauw
- 刊名：Analytical Chemistry
- 出版年：2014
- 出版时间：March 4, 2014
- 年：2014
- 卷：86
- 期：5
- 页码：2451-2457
- 全文大小：392K
- 年卷期：v.86,no.5(March 4, 2014)
- ISSN：1520-6882
文摘
Matrix-assisted laser desorption ionization in-source decay (MALDI-ISD) is a useful method for top-down sequencing of proteins and preferentially produces the c鈥?z鈥?/sup> fragment pair. Subsequently, radical z鈥?/sup> fragments undergo a variety of radical reactions. This work is focused on the chemical properties of the 1,5-diaminonaphthalene (1,5-DAN) adducts on z fragment ions (zn*), which are abundant in MALDI-ISD spectra. Postsource decay (PSD) of the zn* fragments resulted in specific peptide bond cleavage adjacent to the binding site of 1,5-DAN, leading to the preferential formation of y鈥?sub>n鈥? fragments. The dominant loss of an amino acid with 1,5-DAN from zn* can be used in pseudo-MS3 mode to identify the C-terminal side fragments from a complex MALDI-ISD spectrum or to determine missed cleavage residues using MALDI-ISD. Although the N鈥揅伪 bond at the N-terminal side of Pro is not cleaved by MALDI-ISD, pseudo-MS3 via zn* can confirm the presence of a Pro residue.