Figure 1.

Purified, Reconstituted PAPST2 Mediates Time-Dependent ATP, ADP, and PAPS Uptake.

(A) SDS-PAGE of the purified inclusion body proteins (5 µg) used for reconstitution. Recombinant PAPST2 has a calculated molecular weight of ∼40 kD. Approximate molecular weights (in kDa) are shown on the left. IB, purified inclusion body proteins; M, pre-stained molecular weight marker (Thermo Fisher).

(B) Illustration displaying the transport of radiolabeled substrate (Sub*) into ATP-loaded liposomes with reconstituted PAPST2 (blue circle). No transport occurs into nonloaded vesicles. Time-dependent import of 50 µM [α³²P]ATP (C), [α³²P]ADP (D), [³⁵S]PAPS (E) by the purified and reconstituted PAPST2 protein into liposomes loaded with 5 mM ATP (black diamonds) or buffer alone (light gray squares) nonloaded, negative control. Data are the mean of three independent experiments; standard errors are given.