SUMMARY: Active, membrane-bound NADH and succinate oxidase activities with a temperature optimum of 75 C were demonstrated in an extremely thermophilic bacterium. These were relatively stable in cell-free extracts and respiratory particles at 75 C, but at 90 C the half-lives of these oxidase systems were about 15 min in respiratory particles and 80 min in cell-free extracts. The stability of the NADH oxidase in respiratory particles at 90 C was enhanced by 2 M-(NH)SO, 50% (v/v) glycerol and by NADH. A number of other substrates were oxidized by the electron transport system. Respiratory particles contained cytochromes -613, -602, -559, cytochrome and at least one -type cytochrome, -555. The soluble fraction contained at least two -type cytochromes, at least one of which was CO-reactive. The sensitivity of NADH and succinate oxidases to a range of inhibitors was determined.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error