Figure 4.

TcpA and CT production in C6706 and its crp derivative KSK394. Strains were grown at 30°C in LB medium, pH 6.5 (lanes 1, 2, and 4), or pH 8.5 (lanes 3 and 5). For each strain, approximately 2 μg of total protein was subjected to SDS/PAGE, electroblotted to nitrocellulose paper, and probed with anti-TCP antiserum (20). O395, lane 1; C6706, lanes 2 and 3; KSK394, lanes 4 and 5. TcpA is shown by the arrow. The amount of CT in each culture supernatant is expressed at the bottom as ng/mg of protein per ml.