Details

Autor(en) / Beteiligte

• Hernychova, Lenka
• Alexandri, Eleni
• Tzakos, Andreas G.
• Zatloukalová, Martina
• Primikyri, Alexandra
• Gerothanassis, Ioannis P.
• Uhrik, Lukas
• Šebela, Marek
• Kopečný, David
• Jedinák, Lukáš
• Vacek, Jan

Titel

Serum albumin as a primary non-covalent binding protein for nitro-oleic acid

Ist Teil von

• International journal of biological macromolecules, 2022-04, Vol.203, p.116-129

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2022

Quelle

MEDLINE

Beschreibungen/Notizen

• This work explores the interaction of 9/10-nitro-oleic acid (NO2-OA) with human serum albumin (HSA). The molecular mechanism of the biological action of NO2-OA is to our knowledge based on a reversible covalent reaction–Michael addition of nucleophilic amino acid residues of proteins. Since HSA is an important fatty acid transporter, a key question is whether NO2-OA can bind covalently or non-covalently to HSA, similarly to oleic acid (OA), which can interact with the FA1-FA7 binding sites of the HSA molecule. 1H NMR studies and competition analysis with OA and the drugs ibuprofen and warfarin were used to investigate a potential non-covalent binding mode. NO2-OA/HSA binding was confirmed to compete with warfarin for FA-7 with significantly higher affinity. NO2-OA competes with ibuprofen for FA-3 and FA-6, however, in contrast to the situation with warfarin, the binding affinities are not significantly different. The described interactions are based exclusively on non-covalent binding. No covalent binding of NO2-OA to HSA was detected by MS/MS. More detailed studies based on MALDI-TOF-MS and Ellman's assay indicated that HSA can be covalently modified in the presence of NO2-OA to a very limited extent. It was also shown that NO2-OA has a higher affinity to HSA than that of OA. •Nitro-fatty acids interact covalently and/or non-covalently depending on the target protein.•Human serum albumin (HSA) is a nitro-oleic acid binding protein with approx. 7:1 stoichiometry.•HSA preferentially binds NO2-oleic acid non-covalently, just like the parent oleic acid.•Residual modification of Cys34 was found upon nitro-oleic acid treatment at supra-physiological concentration.•HSA could play an important role in the transport/distribution of nitro-fatty acids.