Abstract
Monomers of Photosystem I (PS I) from the thermophilic cyanobacterium Synechococcus elongatus were prepared and characterized. Using both the zwitterionic sulfobetain 12 and the nonionic β-dodecyl maltoside as detergents, PS I was extracted in trimeric form from the thylakoid membrane. The trimers dissociate into monomers during gel-filtration, apparently due to a change in the osmotic pressure. The PS I monomer prepared in β-dodecyl maltoside exhibits the same subunit composition as the trimeric PS I. The preparation in sulfobetain 12, however, leads to the removal of the two hydrophobic subunits K and L from the monomer. Further treatment of this sample with sulfobetain 12 detaches the subunits F, J and M, associated with the disappearance of a 706 nun band in the absorption spectrum. Both the PS I monomer with complete subunit composition and the monomer lacking subunits K and L were crystallized using batch and vapor diffusion techniques with poly(ethylene glycol) as the precipitating agent.
Original language | English (US) |
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Pages (from-to) | 115-120 |
Number of pages | 6 |
Journal | BBA - Bioenergetics |
Volume | 1229 |
Issue number | 1 |
DOIs | |
State | Published - Apr 4 1995 |
Externally published | Yes |
Keywords
- Crystallization
- Monomer preparation
- Photosystem I
- Subunit composition
- Thermophilic cyanobacterium
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Cell Biology