Conformational stability of lactate dehydrogenase from Bacillus thermus-aquaticus [proceedings].

Proteins are synthesized and enzymes can function at surprisingly high temperatures in thermophilic micro-organisms. This temperature is about 90°C in the case of Bacillus thermus-aquaticus (A.T.C.C. 25104). Lactate dehydrogenase (EC 1.1.1.27) was isolated from this micro-organism, and the temperature dependence of the rate of pyruvate reduction and thermodynamic parameters of heat inactivation were comparedwith those of a mesophilic counterpart, namely pig skeletal muscle M4 lactate dehydrogenase, to reveal the difference in conformational stability and to obtain information about the nature of the forces responsible for the enhanced thermostability.