Primaquine and other 8-aminoquinolines have been used to treat malaria, and more recently to treat P. cariiui infections, but the mechanism of action of this class of agents remains undefined. Our studies were designed to use primaquine as an affinity ligand to isolate putative targets for the drug in P. carinii. CNBractivated Sepharose was linked to primaquine under conditions that promoted reaction with the tree amino group of primaquine. A 40 kl) protein from extracts of P. carinii bound with high affinity to this resin and was eluted specifically by primaquine. The protein reacted with polvclonal antibodies specific for P. curinn prut.'ins. No proteins were recovered if histidine or glycine was substituted for primaquine as the affinity ligand, or if extracts of uninfected rat lung were run on the primaquine affinity column. The 40kDa protein from P. carinii had VO-4 amino acid sequence hnmology with rat vimentin, an intermediate filament protein. The 40 kDa protein reacted weakly with an antibody known to react with several vimentin proteins; rat vimentin isolated as a control reacted strongly with the anti-vimentin antibody but failed to react with the polyclonal antibody specific for P. carinii. These results suggest that the 40 kDa protein with high affinity for pnmuquine is a homolog of vimentin from P. carinii.
|Original language||English (US)|
|State||Published - Dec 1 1997|
ASJC Scopus subject areas
- Molecular Biology