Growth phase-dependent variations in the outer membrane protein profile of Brucella melitensis.
Changes in Brucella cell envelope protein profiles were investigated with batch cultures of B. melitensis strain 16M in a 2-litre fermenter. Analysis of expression of outer membrane proteins (OMP) (apparent molecular masses of 10, 16.5, 19, 25-27, 31-34, 36-38 and 89 kDa) and heat-shock protein DnaK (73 kDa) was performed with monoclonal antibodies (mAb) and immunoblotting techniques. Synthesis of the 89-kDa OMP and the heat-shock protein DnaK was invariant during B. melitensis growth. Expression of the 10-, 19- and 36-38-kDa minor OMPs was never detected. Variations in profiles of some OMPs, i.e. 25-27-kDa and 31-34-kDa major proteins and 16.5-kDa minor protein, occurred during growth stages, principally at the end of the exponential growth phase. These variations consisted of shifts in apparent molecular masses for the 25-27-kDa and 31-34-kDa OMPs and of peptidoglycan association for the 16.5-kDa OMP. Therefore, whereas the strong association of major OMPs with peptidoglycan was confirmed, results suggested that the 16.5-kDa minor OMP is also a peptidoglycan-associated protein.
Gallot-Lavallée
T
T
Institut National de la Recherche Agronomique, Laboratoire de Pathologie infectieuse et Immunologie, Nouzilly, France.
Zygmunt
M S
MS
Cloeckaert
A
A
Bézard
G
G
Dubray
G
G
D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D017347:Brucella melitensis / Q000254:growth & development / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism; D015151:Immunoblotting; D066298:In Vitro Techniques; D010457:Peptidoglycan / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D006360:Heat-Shock Proteins; D010457:Peptidoglycan