FIG. 3.

Inhibition of glucose-dependent proton pumping in S. cerevisiae by BM2. (A) T48 cells were incubated at pH 7.0 in the presence or absence of 5 μM BM2 at pH 7.0 and were prepared for proton pumping, as described in Materials and Methods. Proton pumping was initiated at time zero by adding 2% glucose where indicated, and the OD₅₉₀ between 3 and 1 was monitored as an indicator of pH in the range of 5.0 to 3.5. Typical results from a representative experiment are shown. (B) T48 cells preincubated with BM2 at pH 7.0 were assayed for glucose-dependent proton pumping at pH 5, as described for panel A.