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Author: Wende, Kristian × Has files: Yes × Subject: Mass spectrometry × WGL Institute: INP ×

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Now showing 1 - 3 of 3
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    Reactive species driven oxidative modifications of peptides—Tracing physical plasma liquid chemistry
    (Melville, NY : American Inst. of Physics, 2021) Wenske, Sebastian; Lackmann, Jan-Wilm; Busch, Larissa Milena; Bekeschus, Sander; von Woedtke, Thomas; Wende, Kristian
    The effluence of physical plasma consists of a significant share of reactive species, which may interact with biomolecules and yield chemical modifications comparable to those of physiological processes, e.g., post-translational protein modifications (oxPTMs). Consequentially, the aim of this work is to understand the role of physical plasma-derived reactive species in the introduction of oxPTM-like modifications in proteins. An artificial peptide library consisting of ten peptides was screened against the impact of two plasma sources, the argon-driven MHz-jet kINPen and the helium-driven RF-jet COST-Jet. Changes in the peptide molecular structure were analyzed by liquid chromatography–mass spectrometry. The amino acids cysteine, methionine, tyrosine, and tryptophan were identified as major targets. The introduction of one, two, or three oxygen atoms was the most common modification observed. Distinct modification patterns were observed for nitration (+N + 2O–H), which occurred in kINPen only (peroxynitrite), and chlorination (+Cl–H) that was exclusive for the COST-Jet in the presence of chloride ions (atomic oxygen/hypochlorite). Predominantly for the kINPen, singlet oxygen-related modifications, e.g., cleavage of tryptophan, were observed. Oxidation, carbonylation, and double oxidations were attributed to the impact of hydroxyl radicals and atomic oxygen. Leading to a significant change in the peptide side chain, most of these oxPTM-like modifications affect the secondary structure of amino acid chains, and amino acid polarity/functionality, ultimately modifying the performance and stability of cellular proteins.
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    A Neutrophil Proteomic Signature in Surgical Trauma Wounds
    (Basel : Molecular Diversity Preservation International, 2018-3-7) Bekeschus, Sander; Lackmann, Jan-Wilm; Gümbel, Denis; Napp, Matthias; Schmidt, Anke; Wende, Kristian
    Non-healing wounds continue to be a clinical challenge for patients and medical staff. These wounds have a heterogeneous etiology, including diabetes and surgical trauma wounds. It is therefore important to decipher molecular signatures that reflect the macroscopic process of wound healing. To this end, we collected wound sponge dressings routinely used in vacuum assisted therapy after surgical trauma to generate wound-derived protein profiles via global mass spectrometry. We confidently identified 311 proteins in exudates. Among them were expected targets belonging to the immunoglobulin superfamily, complement, and skin-derived proteins, such as keratins. Next to several S100 proteins, chaperones, heat shock proteins, and immune modulators, the exudates presented a number of redox proteins as well as a discrete neutrophil proteomic signature, including for example cathepsin G, elastase, myeloperoxidase, CD66c, and lipocalin 2. We mapped over 200 post-translational modifications (PTMs; cysteine/methionine oxidation, tyrosine nitration, cysteine trioxidation) to the proteomic profile, for example, in peroxiredoxin 1. Investigating manually collected exudates, we confirmed presence of neutrophils and their products, such as microparticles and fragments containing myeloperoxidase and DNA. These data confirmed known and identified less known wound proteins and their PTMs, which may serve as resource for future studies on human wound healing.
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    Protective role of sphingomyelin in eye lens cell membrane model against oxidative stress
    (Basel : MDPI, 2021) Ravandeh, Mehdi; Coliva, Giulia; Kahlert, Heike; Azinfar, Amir; Helm, Christiane A.; Fedorova, Maria; Wende, Kristian
    In the eye lens cell membrane, the lipid composition changes during the aging process: the proportion of sphingomyelins (SM) increases, that of phosphatidylcholines decreases. To investigate the protective role of the SMs in the lens cell membrane against oxidative damage, analytical techniques such as electrochemistry, high-resolution mass spectrometry (HR-MS), and atomic force microscopy (AFM) were applied. Supported lipid bilayers (SLB) were prepared to mimic the lens cell membrane with different fractions of PLPC/SM (PLPC: 1-palmitoyl-2-linoleoylsn-glycero-3-phosphocholine). The SLBs were treated with cold physical plasma. A protective effect of 30% and 44% in the presence of 25%, and 75% SM in the bilayer was observed, respectively. PLPC and SM oxidation products were determined via HR-MS for SLBs after plasma treatment. The yield of fragments gradually decreased as the SM ratio increased. Topographic images obtained by AFM of PLPC-bilayers showed SLB degradation and pore formation after plasma treatment, no degradation was observed in PLPC/SM bilayers. The results of all techniques confirm the protective role of SM in the membrane against oxidative damage and support the idea that the SM content in lens cell membrane is increased during aging in the absence of effective antioxidant systems to protect the eye from oxidative damage and to prolong lens transparency.