Increased chemical acetylation of peptides and proteins in rats after daily ingestion of diacetyl analyzed by Nano-Lc-MS/MS

Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
Institute of Studies in Health and Biological, Collective Health, Universidade Federal do Sul e Sudeste do Pará, Maraba, PA, Brazil
Department of chemistry, Fundação Universidade Federal de Rondônia, Porto Velho, RO, Brazil
São Carlos Institute of Chemistry, Universidade de São Paulo, São Carlos, SP, Brazil
Department of Fundamental Chemistry , Institute of Chemistry, Universidade de São Paulo, São Paulo, SP, Brazil
DOI
10.7287/peerj.preprints.26613v1
Subject Areas
Biochemistry, Toxicology
Keywords
Radical acetylation, diacetyl, food additive, lung diseases, proteomics.
Copyright
© 2018 Jedlicka et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Jedlicka LDL, Guterres SB, Balbino AM, Neto GB, Landgraf RG, Fernandes L, Carrilho E, Bechara EJH, Assuncao NA. 2018. Increased chemical acetylation of peptides and proteins in rats after daily ingestion of diacetyl analyzed by Nano-Lc-MS/MS. PeerJ Preprints 6:e26613v1

Abstract

Background: Acetylation alters several protein properties including molecular weight, stability, enzymatic activity, protein-protein interactions, and other biological functions. Our previous findings demonstrating that diacetyl/peroxynitrite can acetylate L-lysine, L-histidine, and albumin in vitro led us to investigate whether diacetyl-treated rats suffer protein acetylation as well.

Methods: Wistar rats were administered diacetyl daily for 4 weeks, after which they were sacrificed, and their lung proteins were extracted to be analysed by Nano-LC-MS/MS (Q-TOF). A C18 reversed-phase column and gradient elution with formic acid/acetonitrile solutions from 2 to 50% over 150 min were used to separate the proteins. Protein detection was performed using a microTOF-Q II (QTOF) equipped with captive source and an electrospray-ionization source. The data from mass spectrometry were processed using a Compass 1.7 and analyzed using Protein Scape, software that uses Mascot algorithms to perform protein searches.

Results: A set of 3162 acetylated peptides derived from 351 acetylated proteins in the diacetyl-treated group was identified. Among them, 23 targeted proteins were significantly more acetylated in the diacetyl-treated group than in the PBS control. Protein acetylation of the group treated with 540 mg/kg/day of diacetyl was corroborated by Western blotting analysis.

Conclusions: These data support our hypothesis that diacetyl exposure in animals may lead to the generation of acetyl radicals, compounds that attach to proteins, affecting their functions and triggering adverse health problems.

Author Comment

This is a submission to PeerJ for review.

Supplemental Information

NanoHPLC gradient elution

NanoHPLC gradient elution, gradient mobile phase consisting of (A) formic acid/ACN/ H2O (1:20:980) and (B) formic acid/ACN/ H2O (1:950:50)

DOI: 10.7287/peerj.preprints.26613v1/supp-1

Central residue H acetylated (control group)

Motif Analyse of Lung from control group.Central residue H acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-2

Central residue H acetylated in group treated with 540 mg/Kg/day of Diacetyl

Motif Analyse of Lung from group treated with 540 mg/Kg/day of Diacetyl. Central residue H acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-3

Central residue K acetylated in group treated with 540 mg/Kg/day of Diacetyl

Motif Analyse of Lung from group treated with 540 mg/Kg/day of Diacetyl. Central residue K acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-4

Central residue K acetylated in control group

Motif Analyse of Lung from control group. Central residue K acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-5

Central residue R acetylated in group treated with 540 mg/Kg/day of Diacetyl

Mottif Analyse of Lung from group treated with 540 mg/Kg/day of Diacetyl. Central residue R acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-6

Central residue R acetylated in control group

Motif Analyse of Lung from control group. Central residue R acetylated

DOI: 10.7287/peerj.preprints.26613v1/supp-7