FIG. 6.
Aerobically expressed total membrane proteins. Lane 1, molecular mass standard (the molecular masses of the proteins in the standard, in kilodaltons, are indicated on the left); lane 2, strain Hib1 (arcA::kan); lane 3, strain Hib3 (arcA-gfp-tet); lane 4, strain Hib2 (arcA::tet); lane 5, wild-type strain Hib; lane 6, whole-cell lysate. Membrane proteins were prepared, as described in Materials and Methods, from cells grown aerobically in BHI medium. It was difficult to separate the cytoplasmic and outer membrane fractions, probably due to the high capsule content. Therefore, the gels represent the total membrane fraction. The most reproducible differences were the differences in two proteins, formate dehydrogenase (FD) (115 kDa) and l-lactate dehydrogenase (LLD) (42 kDa). Other small differences were observed but were not reproducible. The probable position of porin (P) is also indicated.