Real-time laser induced chemical derivatizations of peptide N-Terminus for in-situ mass spectrometric sequencing at sub-picomole and nanosecond scale.

Autor: Zhang J; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Jia S; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Lu W; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Li W; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Jiang R; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Liu Y; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Yang X; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Zou S; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Zou X; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China., Zhong H; Laboratory of Mass Spectrometry, College of Chemistry, Central China Normal University, Wuhan, Hubei, 430079, PR China; Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, PR China. Electronic address: hyzhong@mail.ccnu.edu.cn.
Jazyk: angličtina
Zdroj: Analytica chimica acta [Anal Chim Acta] 2020 Mar 01; Vol. 1100, pp. 1-11. Date of Electronic Publication: 2019 Dec 13.
DOI: 10.1016/j.aca.2019.12.029
Abstrakt: Distinguishing b- and y-ions is essential to compute amino acid sequences from either N- or C-terminus in mass spectrometry. We described herein a solvent free and real time on-plate derivatization approach that can tag N-terminus of peptides at microliter level with p-chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde for matrix assisted laser desorption ionization mass spectrometry (MALDI MS). Less than 1 μL of sample solutions can be directly mixed with equal volumes of p-chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde and α-cyano-4-hydroxycinnamic acid (CHCA), a matrix compound to co-crystalize with analytes for efficient absorption of laser energy and peptide ionization. When the mixture spotted on the sample plate is irradiated with the 3rd harmonic (355 nm) of Nd 3+ :YAG laser pulses (3 ns width), N-terminal amine groups of peptides instantly react with carbonyl groups of chlorobenzaldehyde or 2-hydroxy-5-methylisophthalaldehyde. Resultant peptides carrying with on-plate formed azomethine group (-CN-) are simultaneously protonated and isolated as precursor ions for subsequent collision-activated dissociation. The mass shift with unique Cl isotopic signature unambiguously distinguishes b ions from y ions and other ions. This method does not need extensive sample preparation and is useful for those samples with limited quantities down to sub-picomole level in sub-microliter volumes. The efficiency was demonstrated with synthetic peptides and tryptic peptides of model proteins. It was found that 2-hydroxy-5-methylisophthalaldehyde provides improved yield for peptides containing lysine residues. Unknown proteins of human saliva and bovine milk as well as phosphopeptides have been identified.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2019 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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