FIG. 5.

Lysine biotinylation of Cgs. Cells of B. abortus 2308 harboring pBA20 were incubated with the membrane-impermeant biotinylation reagent NHS-SS-biotin (Pierce Chemical Co.), as described in Materials and Methods. Cell surface proteins were biotinylated for 2 min (lane S) or 6 min (lane S′). Total cell proteins were biotinylated for 6 min after cell disruption by sonication (lane T). Biotinylated proteins were subjected to SDS—10% PAGE and developed by Western blotting by using horseradish peroxidase-conjugated streptavidin (A). The same membrane was stripped and reprobed with a specific polyclonal antiserum against the Cgs protein (B). The positions of molecular mass standards (in kilodaltons) are indicated on the left.