title: Extreme biophysics: Enzymes under pressure.
abstract: A critical question about piezophilic (pressure-loving) microbes is how their constituent molecules maintain function under high pressure. Here, factors are examined that may lead to the increased activity under pressure in dihydrofolate reductase from the piezophilic Moritella profunda compared to the homologous enzyme from the mesophilic Escherichia coli. Molecular dynamics simulations are performed at various temperatures and pressures to examine how pressure affects the flexibility of the enzymes from these two microbes, since both stability and flexibility are necessary for enzyme activity. The results suggest that collective motions on the 10-ns timescale are responsible for the flexibility necessary for "corresponding states" activity at the growth conditions of the parent organism. In addition, the results suggest that while the lower stability of many enzymes from deep-sea microbes may be an adaptation for greater flexibility at low temperatures, high pressure may enhance their adaptation to low temperatures. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Chemistry, Georgetown University, Washington, DC, 20057.
authors.forename: Qi
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Department of Chemistry, Georgetown University, Washington, DC, 20057.|Geophysical Laboratory, Carnegie Institution for Science, Washington, DC, 20015.
authors.forename: Jocelyn M
authors.initials: JM
authors.lastname: Rodgers
authors.affiliation: Department of Civil and Environmental Engineering, The George Washington University, Washington, DC, 20052.
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Hemley
authors.affiliation: Department of Chemistry, Georgetown University, Washington, DC, 20057.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Ichiye
mesh_terms: D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology*; D007700:Kinetics; D008958:Models, Molecular; D034221:Moritella / Q000737:chemistry / Q000201:enzymology*; D011312:Pressure; D013696:Temperature; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D013762:Tetrahydrofolate Dehydrogenase
keywords: atomic fluctuations; extremophiles; pressure and temperature dependence