Thermostability of membrane systems in organic solvents.
Two multisubunit enzymes of the inner mitochondrial membrane, cytochrome oxidase and the H+-ATPase may be transferred into highly apolar solvents as protein-lipid complexes. At 70 degrees C and an initial water concentration of 13 microliters per ml organic solvent (toluene), the half-life of the ATPase was approx. 11 h, whereas that of cytochrome oxidase was about 100 s. Thermostability of cytochrome oxidase could be increased more than 100-times by decreasing the water concentration to 3 microliters per ml toluene. At this latter concentration of water the half-life of the ATPase at 90, 80 and 70 degrees C was 5, 48 and 96 h, respectively.
Ayala
G
G
de Gómez-Puyou
M T
MT
Gómez-Puyou
A
A
Darszon
A
A
D000818:Animals; D002417:Cattle; D003576:Electron Transport Complex IV; D006358:Hot Temperature; D007425:Intracellular Membranes; D006180:Proton-Translocating ATPases; D012997:Solvents; D013367:Submitochondrial Particles / Q000201:enzymology*; D014050:Toluene; D014867:Water
D012997:Solvents; D014867:Water; D014050:Toluene; D003576:Electron Transport Complex IV; D006180:Proton-Translocating ATPases