Uptake of vanadium and its intracellular metabolism by Coprinellus truncorum mycelial biomass

• Published in: Journal of trace elements in medicine and biology 2024-05, Vol.83, p.127381-127381, Article 127381
• Main Authors: Žižić, Milan, Atlagić, Kristina, Karaman, Maja, Živić, Miroslav, Stanić, Marina, Maksimović, Vuk, Zakrzewska, Joanna
• Format: Article
• Language: English
• Subjects: Coprinellus truncorum; EPR; HPLC; NMR; Phosphate metabolism; Vanadium
• ISSN: 0946-672X; 1878-3252
• DOI: 10.1016/j.jtemb.2024.127381

Fungi absorb and solubilize a broad spectrum of heavy metals such as vanadium (V), which makes them a main route of its entry into the biosphere. V as vanadate (V5+) is a potential medical agent due to its many metabolic actions such as interaction with phosphates in the cell, and especially its insulin-mimetic activity. Antidiabetic activity of V-enriched fungi has been studied in recent years, but the biological and chemical bases of vanadium action and status in fungi in general are poorly understood, with almost no information on edible fungi. This manuscript gives a deeper insight into the interaction of V5+ with Coprinellus truncorum, an edible autochthonous species widely distributed in Europe and North America. Vanadium uptake and accumulation as V5+ was studied by 51V NMR, while the reducing abilities of the mycelium were determined by EPR. 31P NMR was used to determine its effects on the metabolism of phosphate compounds, with particular focus on phosphate sugars identified using HPLC. Vanadate enters the mycelium in monomeric form and shows no immediate detrimental effects on intracellular pH or polyphosphate (PPc) levels, even when applied at physiologically high concentrations (20 mM Na3VO4). Once absorbed, it is partially reduced to less toxic vanadyl (V4+) with notable unreduced portion, which leads to a large increase in phosphorylated sugar levels, especially glucose-1-phosphate (G1P) and fructose-6-phosphate (F6P). Preservation of pH and especially PPc reflects maintenance of the energy status of the mycelium, i.e., its tolerance to high V5+ concentrations. Rise in G1P and F6P levels implies that the main targets of V5+ are most likely phosphoglucomutase and phosphoglucokinase(s), enzymes involved in early stages of G6P transformation in glycolysis and glycogen metabolism. This study recommends C. truncorum for further investigation as a potential antidiabetic agent. [Display omitted] •Vanadate (V5+) enters the mycelia of C. truncorum in the form of monomer.•It is partially reduced to vanadyl (V4+) intracellularly.•31P NMR and HPLC show that vanadate caused the increase of G6P and F6P content.•Vanadate targets glycolytic pathway of glucose metabolism.