Cold-Adapted Enzymes

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,…