New approach for pseudo-MS(3) analysis of peptides and proteins via MALDI in-source decay using radical recombination with 1,5-diaminonaphthalene

Daiki Asakawa; Nicolas Smargiasso; Edwin De Pauw

doi:10.1021/ac403285b

New approach for pseudo-MS(3) analysis of peptides and proteins via MALDI in-source decay using radical recombination with 1,5-diaminonaphthalene

Anal Chem. 2014 Mar 4;86(5):2451-7. doi: 10.1021/ac403285b. Epub 2014 Feb 18.

Authors

Daiki Asakawa¹, Nicolas Smargiasso, Edwin De Pauw

Affiliation

¹ Chemistry Department, Mass Spectrometry Laboratory and GIGA-R, University of Liege , 4000 Liege, Belgium.

PMID: 24512348
DOI: 10.1021/ac403285b

Abstract

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'/z(•) fragment pair. Subsequently, radical z(•) 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'n-1 fragments. The dominant loss of an amino acid with 1,5-DAN from zn* can be used in pseudo-MS(3) 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-Cα bond at the N-terminal side of Pro is not cleaved by MALDI-ISD, pseudo-MS(3) via zn* can confirm the presence of a Pro residue.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

2-Naphthylamine / analogs & derivatives*
2-Naphthylamine / chemistry
Peptides / analysis*
Proteins / analysis*
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*

Substances

Peptides
Proteins
1,5-diaminonaphthalene
2-Naphthylamine