NMR and dynamic light scattering give different diffusion information for short-living protein oligomers. Human serum albumin in water solutions of metal ions.

Autor: Kusova AM; Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan, 420111, Russian Federation. alexakusova@mail.ru., Iskhakova AK; Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan, 420111, Russian Federation., Zuev YF; Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center, Russian Academy of Sciences, Lobachevsky Str., 2/31, Kazan, 420111, Russian Federation.; A. Butlerov Chemical Institute, Kazan Federal University, Kremlevskaya 18, Kazan, 420008, Russian Federation.
Jazyk: angličtina
Zdroj: European biophysics journal : EBJ [Eur Biophys J] 2022 Jul; Vol. 51 (4-5), pp. 375-383. Date of Electronic Publication: 2022 Jun 10.
DOI: 10.1007/s00249-022-01605-0
Abstrakt: Diffusive behavior of human serum albumin (HSA) in the presence of Mg 2+ and Cu 2+ ions was studied by pulsed field gradient nuclear magnetic resonance (PFG NMR) and dynamic light scattering (DLS). According to NMR data yielding measurements of HSA self-diffusion coefficient, a weighted average of the protein monomers and oligomers diffusion mobility in the presence of metal ions was observed. While the short-time collective diffusion measured by DLS showed one type of diffusing species in ion-free HSA solution and two molecular forms of HSA in the presence of metal ions. The light intensity correlation function analysis showed that HSA oligomers have a limited lifetime (lower limit is about 0.4 ms) intermediate between characteristic time scales of PFG NMR and DLS experiments. For a theoretical description of concentration dependence of HSA self- and collective diffusion coefficients, the phenomenological approach based on the frictional formalism of non-equilibrium thermodynamics was used (Vink theory), allowing analysis of the solvent-solute and solute-solute interactions in protein solutions. In the presence of metal ions, a significant increase of HSA protein-protein friction coefficient was shown. Based on theoretical analysis of collective diffusion data, the positive values of second virial coefficients A 2 for HSA monomers were obtained. The A 2 values were found to be higher for the HSA with metal ions compared with the ion-free HSA solution. This is due to the more pronounced contribution of repulsion in protein-protein interactions of HSA monomers in the presence of Mg 2+ and Cu 2+ ions.
(© 2022. European Biophysical Societies' Association.)
Databáze: MEDLINE
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