Effect of acclimation temperature on Km values towards GDP-mannose of the microsomal dolichol phosphate mannosyltransferase activity of trout liver (Salmo gairdnerii)

Apparent Km value for GDP-mannose remained stable when trout were raised and when enzyme activity was assayed at temps corresponding to the natural biological temp (between 5 and 15 degrees C). The Km value increased when the temperature of the assay was higher than 21 degrees C. Marked increase of the Km value was observed when trout were acclimated at 21 degrees C, whatever the temperature of the assay between 5 and 30 degrees C.