Reconstitution of phosphate-linked antiport from Streptococcus lactis

Membrane protein solubilized by octyl-beta-D-glucopyranoside in the presence of dispersed phospholipid was incubated with bath-sonicated liposomes and additional detergent. The proteoliposomes formed on dilution showed transport and exchange properties consistent with a reconstitution of phosphate:sugar 6-phosphate antiport. Thus, phosphate self-exchange was found only when protein from induced cells was used; this exchange was blocked by a sugar 6-phosphate, not by a sugar 1-phosphate; and proteoliposomes supported an accumulation of 2-deoxyglucose 6-phosphate with no added source of energy. Solubilization and reconstitution of protein was most effective when performed in the presence of gram-positive phospholipids.