title: Temperature acclimation of Mg2+Ca2+-myofibrillar ATPase from a cold-selective teleost, Salvelinus fontinalis: a compromise solution.
abstract: Brook trout (Salvelinus fontinalis, Mitchill) were acclimated over 15 weeks to either +4 degrees C or +24 degrees C. The effects of temperature on myofibrillar Mg2+Ca2+-ATPase activities were investigated. In contrast to goldfish, temperature acclimation does not alter the kinetic properties of the brook trout myofibrillar ATPase. Activation energy (delta G not equal to) is lower and substrate turnover number is higher than values previously reported for cold-adapted stenotherms. Properties of brook trout ATPase appear to be a compromise enabling function across a broad temperature range. The different strategies of adapting to seasonal temperature variations are briefly discussed.
mesh_terms: D000064:Acclimatization; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D007700:Kinetics; D009210:Myofibrils / Q000201:enzymology; D012487:Salmonidae / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics; D014337:Trout / Q000378:metabolism*
chemical_list: D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases