Observation of the multiple halogenation of peptides in the electrospray ionization source.
The chlorination of peptides and proteins is an important posttranslational modification, which is a physiological signature of an enzyme myeloperoxidase and can serve as a potential biomarker of some diseases (Parkinson's disease, Alzheimer's disease, etc.). The quantification of the chlorinated peptides has been very challenging in part due to their low levels and artifacts associated with sample preparation. One of the most convenient and promising methods to detect and investigate the chlorinated peptides in the biological samples is the electrospray ionization (ESI) mass spectrometry coupled to the fragmentation techniques (collision-induced dissociation and electron capture dissociation/electron transfer dissociation). We have shown that if the chlorine anions are present in the solution, then the peptide can undergo the chlorination during the ESI ionization. The effect was found to depend on the values of electric potentials of metal parts of the ESI interface. It was found that the grounding of ESI syringe results in the formation of an additional electric loop leading to the electrolytic production of Cl2 and as a consequence the hypochlorous acid inside the ESI needle. Hypochlorous acid reacts with amino groups of peptides and proteins producing chloramine or causing the protein cleavage. In the paper, it is shown on the example of the solution of the several peptides in the presence of HCl that by manipulating the ESI syringe potential, it is possible to create complexes with up to five Cl atoms for sample peptides when the ESI is operated in the positive mode.
Skolkovo Institute of Science and Technology, Novaya St., 100, Skolkovo, 143025, Russia.|Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Leninskij pr. 38 k.2, 119334, Moscow, Russia.|Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.
Yury
Y
Kostyukevich
Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Leninskij pr. 38 k.2, 119334, Moscow, Russia.|Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.
Ekaterina
E
Zhdanova
Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Leninskij pr. 38 k.2, 119334, Moscow, Russia.|Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.
Alexey
A
Kononikhin
Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.|Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Kosygina st. 4, 119334, Moscow, Russia.
Igor
I
Popov
Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.|Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Kosygina st. 4, 119334, Moscow, Russia.
Eugene
E
Kukaev
Skolkovo Institute of Science and Technology, Novaya St., 100, Skolkovo, 143025, Russia.|Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Leninskij pr. 38 k.2, 119334, Moscow, Russia.|Moscow Institute of Physics and Technology, 141700, Dolgoprudnyi, Moscow Region, Russia.|Emanuel Institute for Biochemical Physics, Russian Academy of Sciences, Kosygina st. 4, 119334, Moscow, Russia.
Eugene
E
Nikolaev
D054879:Halogenation; D006997:Hypochlorous Acid / Q000737:chemistry*; D010455:Peptides / Q000032:analysis* / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D010455:Peptides; D006997:Hypochlorous Acid
FT ICR; adduct formation; chlorine; electrospray; peptides