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Use of deuterium labeling by high‐temperature solid‐state hydrogen‐exchange reaction for mass spectrometric analysis of bradykinin biotransformation
Author(s) -
Kopylov Arthur T.,
Myasoedov Nikolay F.,
Dadayan Alexander K.,
Zgoda Victor G.,
Medvedev Alexei E.,
Zolotarev Yurii A.
Publication year - 2016
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7558
Subject(s) - chemistry , deuterium , mass spectrometry , hydrogen–deuterium exchange , chromatography , electrospray ionization , peptide , electrospray , biochemistry , physics , quantum mechanics
Rationale Studies of molecular biodegradation by mass spectrometry often require synthetic compounds labeled with stable isotopes as internal standards. However, labeling is very expensive especially when a large number of compounds are needed for analysis of biotransformation. Here we describe an approach for qualitative and quantitative analysis using bradykinin (BK) and its in vitro degradation metabolites as an example. Its novelty lies in the use of deuterated peptides which are obtained by a high‐temperature solid‐state exchange (HSCIE) reaction. Methods Deuterated and native BK were analyzed by positive electrospray ionization high‐resolution mass spectrometry (ESI‐HRMS) using an Orbitrap Fusion mass spectrometer. High‐energy collision‐induced dissociation (HCD) experiments were performed on [M+H] + and [M+2H] 2+ ions in targeted‐MS 2 mode with adjusted normalized HCD value. Results After the HSCIE reaction, each amino acid residue of the deuterated peptide contained deuterium atoms and the average degree of substitution was 5.5 atoms per the peptide molecule. The deuterated peptide demonstrated the same chromatographic mobility as the unlabeled counterpart, and lack of racemization during substitution with deuterium. Deuterium‐labeled and unlabeled BKs were incubated with human plasma and their corresponding fragments BK(1‐5) and BK(1‐7), well known as the major metabolites, were detected. Conclusions Quantitative assays demonstrated applicability of the heavy peptide for both sequencing and quantification of generated fragments. Applicability of the HSCIE deuterated peptide for analysis of routes of its degradation has been shown in in vitro experiments. Copyright © 2016 John Wiley & Sons, Ltd.