Figure 6.

Kinetics of [³H]SAM transport in proteoliposomes reconstituted with SAMC1. A, Uptake of SAM. 1 mm [³H]SAM was added to proteoliposomes containing 10 mm SAM (exchange, •) or 5 mm NaCl and no substrate (uniport, ○). Data are means ± sd for three independent experiments. B, Efflux of [³H]SAM from proteoliposomes reconstituted in the presence of 1 mm SAM. The internal substrate pool was labeled with [³H]SAM by carrier-mediated exchange equilibration. Then the proteoliposomes were passed through Sephadex G-75. The efflux of [³H]SAM was started by adding buffer A alone (•) or 5 mm SAM in buffer A (○). Data are means ± sd for three independent experiments.