title: Psychrophilic enzymes: a thermodynamic challenge.
abstract: Psychrophilic microorganisms, hosts of permanently cold habitats, produce enzymes which are adapted to work at low temperatures. When compared to their mesophilic counterparts, these enzymes display a higher catalytic efficiency over a temperature range of roughly 0-30 degrees C and a high thermosensitivity. The molecular characteristics of cold enzymes originating from Antarctic bacteria have been approached through protein modelling and X-ray crystallography. The deduced three-dimensional structures of cold alpha-amylase, beta-lactamase, lipase and subtilisin have been compared to their mesophilic homologs. It appears that the molecular adaptation resides in a weakening of the intramolecular interactions, and in some cases in an increase of the interaction with the solvent, leading to more flexible molecular edifices capable of performing catalysis at a lower energy cost.
authors.affiliation: Laboratory of Biochemistry, Institute of Chemistry, University of Liège, Belgium. ch.gerday@ulg.ac.be
authors.forename: C
authors.initials: C
authors.lastname: Gerday
authors.forename: M
authors.initials: M
authors.lastname: Aittaleb
authors.forename: J L
authors.initials: JL
authors.lastname: Arpigny
authors.forename: E
authors.initials: E
authors.lastname: Baise
authors.forename: J P
authors.initials: JP
authors.lastname: Chessa
authors.forename: G
authors.initials: G
authors.lastname: Garsoux
authors.forename: I
authors.initials: I
authors.lastname: Petrescu
authors.forename: G
authors.initials: G
authors.lastname: Feller
mesh_terms: D000864:Antarctic Regions; D001419:Bacteria / Q000201:enzymology*; D003080:Cold Temperature; D003454:Cryptococcus / Q000201:enzymology; D013816:Thermodynamics