PhD Student: Procedure no. DSMBBC/2026/09: Biological membrane as actor in copper biochemistry: chemical models,neuromodulators and a validating bioassay. Chemical aspects

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PhD Student: Procedure no. DSMBBC/2026/09: Biological membrane as actor in copper biochemistry: chemical models,neuromodulators and a validating bioassay. Chemical aspects Sintesi in italiano (traduzione automatica): L'organizzazione internazionale cerca un Dottorando in Chimica per un progetto che esplora l'influenza delle membrane biologiche sulla biochimica del rame. Il candidato lavorerà presso la sede dell'ente e si occuperà di sintetizzare peptidi, studiare l'affinità di legame del rame con neuromodulatori e caratterizzare strutturalmente i complessi. Sarà fondamentale l'uso di metodi fisico-chimici per comprendere le interazioni tra i peptidi e gli ioni di rame. È richiesta una laurea in Chimica o un campo correlato. Il progetto prevede nove compiti principali, con un focus particolare sulle prime sette attività, che includono la sintesi di peptidi e studi di interazione in ambienti micellari. The goal of this project is to elucidate the influence of phospholipid bilayers and their models on interactions of biological peptides and related molecules with copper ions. This knowledge is required to better understand the processes involving copper signaling in health and disease. Biological compartments, relevant to copper signaling, including synapses, have very high surface to volume aspects, resulting in copper complexes present in the vicinity of the membrane. Still, their interactions are barely known. We will use exact physicochemical methods, to establish whether the phospholipid membrane may influence the biological chemistry of Cu2+/Cu+ ions. The obtained knowledge will contribute to designing innovative metallodrugs and therapies. The project will consist of nine tasks: 1. Peptide synthesis. Peptidic neuromodulators, Aβ species, NKB, NMC, hepcidin and other disulfide neuropeptides will be synthesized according to Fmoc strategy. Trp mutants and shorter model peptideswill be also obtained. 2. The effect of micellar environment on the Cu(II) binding affinity of neuromodulators. Equilibrium constants of Cu(II) complexes with neuromodulators will be determined in micellar systems. 3. Structural characterization of selected complex/micelle systems. This will be accomplished by NMR, including 19F spectra for Cu(II) complexes and isostructural Cu(II) replacements with diamagnetic Ni(II) or Pd(II). 4. Susceptibility of selected complex/micelle systems to competition from small hydrophilic ligands. The expected weakening of Cu(II) binding affinity of neuromodulators may make them susceptible to competition neurotransmitters, including glutamic acid, histidine, carnosine, taurine, dopamine, acetylcholine, noradrenaline, serotonin, and short histidine peptides. 5. Susceptibility of selected complex/micelle systems to reducing agents. Cu(II) complexes must be reduced to Cu(I) for hCtr1 transport. This will be tested using GSH, cysteine and ascorbate. The interference by small competitors and Zn2+ ions will also be studied. 6. The effect of micellar environment on the kinetics of exchange of Cu(II) ions between neuromodulators and other synaptic ligands. This will be studied by stopped-flow. Reactions faster than 2 ms will be approached by freeze quench kinetics coupled with EPR. Competition between Zn(II) and Cu(II)/Cu(I) ions will also be studied. 7. Synthesis of O-dodecylserine (ODS) and creation of Cu(II)-binding micelles. ODS will be synthesized for the first time, to serve as SDS-compatible analog of phosphatidylserine, a Cu(II) binding phospholipid. Its ability to form micelles will be tested, followed by studies of Cu(II) binding, competition with neuromodulators, redox and kinetic studies. 8. Interactions of Cu(II) complexes with negatively charged, neutral and Cu(II)-binding liposomes. Unilamellar liposomes will be prepared using phospholipids with distinct types of polar heads, followed by Trp fluorescence assays to test whether the interactions in liposomes correspond to micellar systems. 9. Cellular test of suitability of neuromodulators for copper delivery to cells. We developed an innovative protocol for “clean” exposure of HEK293 culture to Cu(II) complexes in a medium free environment, empowering the chemically selective interaction of these complexes with hCtr1. Promising complexes from previous tasks will be verified here. The main focus of the PhD candidate will be on Tasks 1 - 7 Annuncio in inglese. Fonte: Euraxess (Commissione europea).