title: Combined effects of temperature, pressure, and co-solvents on the polymerization kinetics of actin.
abstract: In vivo studies have shown that the cytoskeleton of cells is very sensitive to changes in temperature and pressure. In particular, actin filaments get depolymerized when pressure is increased up to several hundred bars, conditions that are easily encountered in the deep sea. We quantitatively evaluate the effects of temperature, pressure, and osmolytes on the kinetics of the polymerization reaction of actin by high-pressure stopped-flow experiments in combination with fluorescence detection and an integrative stochastic simulation of the polymerization process. We show that the compatible osmolyte trimethylamine-N-oxide is not only able to compensate for the strongly retarding effect of chaotropic agents, such as urea, on actin polymerization, it is also able to largely offset the deteriorating effect of pressure on actin polymerization, thereby allowing biological cells to better cope with extreme environmental conditions.
authors.affiliation: Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 6, 44227 Dortmund (Germany).
authors.forename: Christopher
authors.initials: C
authors.lastname: Rosin
authors.affiliation: Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 6, 44227 Dortmund (Germany).
authors.forename: Kathrin
authors.initials: K
authors.lastname: Estel
authors.affiliation: Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 6, 44227 Dortmund (Germany).
authors.forename: Jessica
authors.initials: J
authors.lastname: Hälker
authors.affiliation: Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Otto-Hahn-Str. 6, 44227 Dortmund (Germany). roland.winter@tu-dortmund.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Winter
mesh_terms: D000199:Actins / Q000737:chemistry*; D007700:Kinetics; D058105:Polymerization; D011312:Pressure; D012997:Solvents / Q000737:chemistry*; D013696:Temperature
chemical_list: D000199:Actins; D012997:Solvents
keywords: actin; fluorescence spectroscopy; polymerization; trimethylamine-N-oxide; urea