Towards understanding the crystallization of photosystem II: influence of poly(ethylene glycol) of various molecular sizes on the micelle formation of alkyl maltosides.

Autor: Müh F; Institut für Theoretische Physik, Johannes Kepler Universität Linz, Altenberger Strasse 69, 4040, Linz, Austria. frank.mueh@jku.at., Bothe A; Institut für Molekularbiologie und Biophysik, ETH Zürich, HPK, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland., Zouni A; Institut für Biologie, Humboldt Universität zu Berlin, Leonor-Michaelis-Haus, Philippstrasse 13, 10095, Berlin, Germany.
Jazyk: angličtina
Zdroj: Photosynthesis research [Photosynth Res] 2024 Dec; Vol. 162 (2-3), pp. 273-289. Date of Electronic Publication: 2024 Mar 15.
DOI: 10.1007/s11120-024-01079-5
Abstrakt: The influence of poly(ethylene glycol) (PEG) polymers H-(O-CH 2 -CH 2 ) p -OH with different average molecular sizes p on the micelle formation of n-alkyl-β-D-maltoside detergents with the number of carbon atoms in the alkyl chain ranging from 10 to 12 is investigated with the aim to learn more about the detergent behavior under conditions suitable for the crystallization of the photosynthetic pigment-protein complex photosystem II. PEG is shown to increase the critical micelle concentration (CMC) of all three detergents in the crystallization buffer in a way that the free energy of micelle formation increases linearly with the concentration of oxyethylene units (O-CH 2 -CH 2 ) irrespective of the actual molecular weight of the polymer. The CMC shift is modeled by assuming for simplicity that it is dominated by the interaction between PEG and detergent monomers and is interpreted in terms of an increase of the transfer free energy of a methylene group of the alkyl chain by 0.2 kJ mol -1 per 1 mol L -1 increase of the concentration of oxyethylene units at 298 K. Implications of this effect for the solubilization and crystallization of protein-detergent complexes as well as detergent extraction from crystals are discussed.
Competing Interests: Declarations. Conflict of interest: The authors have no competing interests to declare that are relevant to the content of this article.
(© 2024. The Author(s).)
Databáze: MEDLINE
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