|
KMID : 0365819670070020059
|
|
Journal of Pusan Medical College
1967 Volume.7 No. 2 p.59 ~ p.68
|
|
|
Studies on the Stability of Oxidative Phosphorylation in Rabbit Liver Mitochondria
|
|
|
|
|
Abstract
|
|
|
The capacity for oxidative phosphorylation is generally regarded as one of the most significant biochemical properties of mitochondria.
The numerous biochemical investigations of isolated mitochondria that have revealed this property also have led to the widely accepted tenet that these organelles are unstable entitites when isolated. For example, such seemingly mild procedures as freezing, brief incubation at 37°C in the absence of oxidizable substrate, or prolonged storage at low temperature has been reported to result in almost complete loss of the phosphorylative activity. Although there are a few incidental observation that this instability is not an invariant attributed liver mitochondria, the effect of the fluctuations of temperature(-3°C?15°C for ten minutes) during the isolation procedure upon the oxidative phosphorylation in the presence of some biochemical substances in the isolation medium has not been extensively investigated.
Mitochondria were isolated from the rabbit liver in 0. 25M sucrose essentially by the differential centrifugation technique of Schneider.
The results are as follows:
1. The concentration of sucrose in the isolation medium has a great influence on the stability of the oxidative phosphorylation. 0. 25M sucrose is the optimal concentration, but both higher and lower concentration are detrimental.
2. Twice washing of mitochondria showed the highest P:0 ratio, but both increasing and decreasing of washing times resulted in the decline of the P.O ratio.
3. Freezing and thawing of mitochondrial preparations during the isolation procedure revealed a complete loss. of the oxidative phosphorylation activity.
4. The loss of oxidative phosphorylation activity may be almost completely reversed by adding bovine serum, R N A and fructose-1, 6-diphosphate to the isolation medium.
5. The loss of oxidative phosphorylation activity may be partially reversed by adding the -SH containing compounds, a few members of T C A cycle? some proteins, nucleic acids, and pharmacological substance to the isolation medium.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|