FIG. 2.

Expression and purification of gp15 and gp3. After SDS-PAGE, the gel was stained with Coomassie brilliant blue G. Lane 1, T4 tail used as a molecular mass marker; lanes 2 and 3, expression of gp15 and gp3 from a coexpression vector before and after IPTG induction, respectively (both gp15 and gp3 were expressed in soluble fractions); lanes 4 and 5, purified gp15 and gp3 after gel filtration, respectively (the two proteins were expressed from the respective expression vectors [see Materials and Methods for details]); lanes 6 and 7, peak fractions of gp15 (fraction no. 39) and gp3 (fraction no. 46) from gel filtration (Superdex 200 column) chromatography, respectively (gp15 and gp3 were eluted in different fractions, indicating that they were not interacting or only very weakly interacting); lane 8, molecular mass standards. The bands of gp15 and gp3 are indicated by bold arrows.