Thermococcus profundus

A large number of hyperthermophilic Archaebacteria, especially the deep sea Thermococcale and Sulfolobus species elaborate a-amylases.79-82 Many have been cloned and sequenced.78 Pyrococcus furiosus,83,84 Thermococcus profundus,85 Thermococcus hydrothermalis,78 Sulfolobus solfataricus and Sulfolobus acidocaldar-iusS6 secrete thermophilic a-amylases. The a-amylases of all of these organisms have optimal enzyme activity at 90°C or higher and often only begin to show activity at 40°C or 50°C. Pyrococcus furiosus secretes an a-amylase with an optimum temperature of 100°C and a maximum temperature of 140°C.87 The optimum pH values vary between 5 and 9. Table 7.1 summarizes the names of the organisms, the optimum temperature, and optimum pH values for several of these enzymes. 

Most of the NOXs described in the Hterature selectively oxidize NADH, whereas only few enzymes are able to oxidize both NADH and NADPH, such as the oxidases produced by Therrmcoccus kodakarensis [48], Lactobacillus sanfranciscensis [49], or Thermococcus profundus [58]. In any case, the specific activity for NADH is always much higher than the one for NADPH. 

---