title: Cold-adapted enzymes.
abstract: By far the largest proportion of the Earth's biosphere is comprised of organisms that thrive in cold environments (psychrophiles). Their ability to proliferate in the cold is predicated on a capacity to synthesize cold-adapted enzymes. These enzymes have evolved a range of structural features that confer a high level of flexibility compared to thermostable homologs. High flexibility, particularly around the active site, is translated into low-activation enthalpy, low-substrate affinity, and high specific activity at low temperatures. High flexibility is also accompanied by a trade-off in stability, resulting in heat lability and, in the few cases studied, cold lability. This review addresses the structure, function, and stability of cold-adapted enzymes, highlighting the challenges for immediate and future consideration. Because of the unique properties of cold-adapted enzymes, they are not only an important focus in extremophile biology, but also represent a valuable model for fundamental research into protein folding and catalysis.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia. k.siddiqui@unsw.edu.au
authors.forename: Khawar Sohail
authors.initials: KS
authors.lastname: Siddiqui
authors.forename: Ricardo
authors.initials: R
authors.lastname: Cavicchioli
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D003080:Cold Temperature; D004795:Enzyme Stability; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism*; D008433:Mathematics; D011487:Protein Conformation; D017510:Protein Folding; D055672:Static Electricity; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D004798:Enzymes