Malondialdehyde-Induced Post-translational Modifications in Hemoglobin of Smokers by NanoLC–NSI/MS/MS Analysis

• Published in: Journal of proteome research Vol. 21; no. 12; pp. 2947 - 2957
• Main Authors: Chen, Hauh-Jyun Candy, Chen, Chau-Yi, Fang, Ya-Hsuan, Hung, Kai-Wei, Wu, Deng-Chyang
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 02.12.2022
• Subjects: Biomarkers - metabolism; Hemoglobins - chemistry; Humans; Lysine - metabolism; Malondialdehyde; Protein Processing, Post-Translational; Smokers; Tandem Mass Spectrometry; posttranslational modifications; malondialdehyde; biomarker; selected reaction monitoring; hemoglobin; smoking
• ISSN: 1535-3893; 1535-3907; 1535-3907
• DOI: 10.1021/acs.jproteome.2c00442

Malondialdehyde (MDA) is the most abundant α,β-unsaturated aldehyde generated from endogenous peroxidation of polyunsaturated fatty acids and is present in cigarette smoke. Post-translational modifications of blood hemoglobin can serve as biomarkers for exposure to chemicals. In this study, two types of MDA-induced modifications, the N-propenal and the dihydropyridine (DHP), were identified at multiple sites in human hemoglobin digest by the high-resolution mass spectrometry. The N-propenal and the DHP types of modification led to the increase of 54.0106 and 134.0368 amu, respectively, at the N-terminal and lysine residues. Among the 21 MDA-modified peptides, 14 with dose–response to MDA concentrations were simultaneously quantified in study subjects by the nanoflow liquid chromatography nanoelectrospray ionization tandem mass spectrometry under selected reaction monitoring (nanoLC–NSI-MS/MS-SRM) without prior enrichment. The results showed that the modifications of the N-propenal-type at α-Lys-11, α-Lys-16, α-Lys-61, β-Lys-8, and β-Lys-17, as well as the DHP-type at the α-N-terminal valine, are significantly higher in hemoglobin isolated from the blood of smokers than in nonsmoking individuals. This is the first report to identify and quantify multiple sites of MDA-induced modifications in human hemoglobin from peripheral blood. Our results suggest that the MDA-derived modifications on hemoglobin might represent valuable biomarkers for MDA-induced protein damage.