N. Gotoh et al., ISOLATION AND CHARACTERIZATION OF THE OUTER-MEMBRANE PROTEINS OF BURKHOLDERIA (PSEUDOMONAS) PSEUDOMALLEI, Microbiology, 140, 1994, pp. 797-805
Membranes obtained from whole-cell lysates of Burkholderia (Pseudomona
s) pseudomallei (strain 319a) were separated into four fractions by su
crose density gradient centrifugation. Membranes were characterized by
enzymic and chemical analyses, and by SDS-PAGE. Cytoplasmic membranes
and two forms of outer membranes (OM-1, OM-2) were detected. The majo
r outer-membrane proteins had M(r) values of 70000, 38000, 31000, 2400
0 and 17000. To determine which outer-membrane proteins were common to
B. pseudomallei strains, OM-1 fractions from 12 different strains wer
e prepared. SDS-PAGE analysis of these fractions demonstrated that the
five major outer-membrane proteins were common to the strains tested.
Further studies have shown that an M(r) 110000 protein, which is olig
omeric in that it migrates as an M(r) 38000 protein upon heating at 95
degrees C and which is peptidoglycan-associated, serves as a porin in
B. pseudomallei. Using proteoliposomes reconstituted from this protei
n and phospholipid, it was demonstrated by the liposome-swelling assay
that this protein acts as a porin through which small saccharides may
diffuse. Further characterization of this M(r) 38000 protein will be
important in delineating the role of this molecule in the permeability
of the B, pseudomallei outer membrane.