SELECTIVE EXTRACTION OF OUTER-MEMBRANE PROTEINS FROM MEMBRANE COMPLEXES OF PSEUDOMONAS-MALTOPHILA BY CHLOROFORM METHANOL

An organic phase partitioning method is described for the selective purification of outer-membrane proteins (OMPs) from the total membrane complex of the opportunistic human and sheep pathogen, Pseudomonas maltophila. SDS-PAGE analysis confirmed that OMPs purified by chloroform-methanol treatment of the total membrane complex were not only identical to OMPs extracted from outer-membrane vesicles separated by sucrose gradient density centrifugation, but also possessed little or non-detectable levels of inner-membrane contaminants. Further analysis by enzyme linked immunosorbent assay (ELISA) and immunoblotting established that OMPs extracted by organic phase partitioning with chloroform-methanol retained antigenicity and serological activity indistinguishablee from OMPs that were present in outer-membrane vesicles resolved by isopycnic sucrose density centrifugation of sarkosyl-treated membrane complexes. © 1990.