FIG. 4.

Recognition of XylR and TouR in Western blots by Phab B7. Different protein preparations were separated by denaturing SDS-PAGE (10%), transferred to a PVDF membrane, and probed with the antibodies and Phabs indicated. (A) Different amounts of purified _6xhisTouRΔA (50, 16.6, 5.5, 1.8, and 0.61 ng [lanes 1 to 5, respectively]) were probed with a serum obtained from immunized mice (α-TouRΔA; top panel), Phab B7 (middle panel), or Phab MBP (as a negative control; bottom panel). (B) A mixture of 10 ng of purified _6xhisTouRΔA and _6xhisTouR (lane 1) or 30 ng of _6xhisXylRΔA and _6xhisXylR (lane 2) was probed with Phab B7. (C) Whole-cell protein extracts from P. stutzeri OX1 (lane 1) or P. putida KT2442 (lane 2) were probed with Phab B7. In all cases, the bound antibodies or Phabs were developed with anti-mouse-peroxidase or anti-M13-peroxidase conjugates, respectively.