Elucidation of Plasma-induced Chemical Modifications on Glutathione and Glutathione Disulphide

Abstract

Cold atmospheric pressure plasmas are gaining increased interest in the medical sector and clinical trials to treat skin diseases are underway. Plasmas are capable of producing several reactive oxygen and nitrogen species (RONS). However, there are open questions how plasma-generated RONS interact on a molecular level in a biological environment, e.g. cells or cell components. The redox pair glutathione (GSH) and glutathione disulphide (GSSG) forms the most important redox buffer in organisms responsible for detoxification of intracellular reactive species. We apply Raman spectroscopy, mass spectrometry, and molecular dynamics simulations to identify the time-dependent chemical modifications on GSH and GSSG that are caused by dielectric barrier discharge under ambient conditions. We find GSSG, S-oxidised glutathione species, and S-nitrosoglutathione as oxidation products with the latter two being the final products, while glutathione sulphenic acid, glutathione sulphinic acid, and GSSG are rather reaction intermediates. Experiments using stabilized pH conditions revealed the same main oxidation products as were found in unbuffered solution, indicating that the dominant oxidative or nitrosative reactions are not influenced by acidic pH. For more complex systems these results indicate that too long treatment times can cause difficult-to-handle modifications to the cellular redox buffer which can impair proper cellular function.

Impact of plasma oxidation on structural features of human epidermal growth factor

“…While the presented spectra do not perfectly agree, most likely due to different buffers as well as pH conditions, it is apparent that disulfide bonds play a major role in determining the secondary structure of hEGF. Taking into account the strong impact of DBD treatment on disulfide bonds and its capability to oxidize disulfide bonds to, for example, cysteine sulfonic acid (R‐SO 3 H), differences in CD spectra might be due to the formation of sulfur‐containing residues all with a negative charge, thereby further promoting unfolding of the structure, as shown for longer treatment times. The additional introduction of C═O bounds, as indicated by FTIR spectroscopy, might also assist in the unfolding process.…”

On a heavy path – determining cold plasma-derived short-lived species chemistry using isotopic labelling

“…46,47 Thiol groups are one of the major targets for plasma-generated species. [48][49][50] Hence, CAP impact can yield to (non-enzymatic) post-translational modications (PTMs), with some of which transport signicant inuence in cellular signaling. [51][52][53][54] However, so far no specic member of the various ROS or RNS could be attributed to be the major driver of these reactions.…”

Aqueous‐Solution‐Based Approach Towards Carbon‐Free Sb2S3 Films for High Efficiency Solar Cells

“…[26] The appearance of these peaks indicates the formation of aS b ÀS complex (II), as shown in Reaction (3). [27] In this case, it suggested that an acylamide bond is formed in molecular structure (III) (Reaction (4);F igure 1b). [27] The peak was diminished as the annealing temperature (AT) was increased, indicating the breaking of the CÀSb ond.…”

“…[25] Moreover,R amans cattering at 300 cm À1 was ascribed to C 3v symmetric modes of the SbS 3 pyramid structure. [27] The peak was diminished as the annealing temperature (AT) was increased, indicating the breaking of the CÀSb ond. The resonant peak located at 660 cm À1 is assigned to the CÀSs tretching vibration.…”