Trehalose, an extreme temperature protector of phosphoenolpyruvate carboxylase from the C4-plant Cynodon dactylon

High concentration (1.25 M) of trehalose fully protects the activity of phosphoenolpyruvate carboxylase (PEPC, E C 4.1.1.31) from the C-4-plant Cynodon dactylon against cold inactivation (at 0 degrees) and heat inactivation (at 37 degrees). The concentration of glycerol needed for the same degree of protection was much higher (2.7 M). Phosphates at 100 mM only partially protect the enzyme against cold inactivation and at 60 mM fully protect it against heat inactivation. At temperatures higher than 45 degrees the enzyme was better protected by trehalose than glycerol or phosphates. (C) 1997 Elsevier Science Ltd.