Partition in aqueous dextran-polyethylene glycol two-phase system was used to isolate the plasma membranes from the alkalophilic cyanobacterium Spirulina platensis. The upper phase contained a colorless membranes obtained in relatively short time, 3-4 h. This fraction had a different protein profile than that of the thylakoid fraction obtained in the lower phase. It did not contain cytochrome c-oxidase activity, but retained characteristic Mg2+-ATPase activity that is sensitive to vanadate, stimulated by K+, and has a pH optimum near 8.5. These data support our assumption that the upper phase of the gradient consist of the plasma membrane of S. platensis.
|Number of pages||5|
|Journal||Plant and Cell Physiology|
|State||Published - 1 Jan 1994|
- ATPase activity
- Phase partition
- Plasma membrane
- Spirulina platensis