Mechanisms and Applications of Enzymatic Thermostability

Imagine a hot summer day. What happens when the temperature climbs to a point above 100° F (38° C)? Depending on the place and the typical weather found in that location, reactions vary. Ice cream sales will probably go up. People may curse global warming as they seek shade. Others will head for the beach or community pool. Most forms of life, including human beings, aren't accustomed to that level of heat. One special group of microorganisms, however, would find 100° F heat downright chilly. They are far more comfortable in temperatures nearly three times as warm as the hottest summer day. These thermophilic creatures live mostly in aqueous habitats near 70-80° C, yet a few specimens thrive in water at temperatures above the boiling point. How any living thing could continue to function under these conditions is a mystery, as most enzymes and other proteins necessary for life are denatured and/or destroyed at such high temperatures. Obviously, some stabilizing structural feature unique to thermophilic proteins must be the key to survival for the thermophilic organisms.