Differential effects of detergents and dimethylsulfoxide on membrane prostaglandin E 1 and F 2α receptors

Abstract

Pretreatment of membranes for 1 hr at 4° with up to 0.1% Triton X-100 (TX-100) and sodium desoxycholate (SDC), resulted in a greater loss of [ 3H] prostaglandin (PG)F 2α binding compared to E 1 binding. Lubrol WX (LWX) tended to cause a greater loss of [ 3H]PGF 2α than E 1 binding. However, the differential loss was not as marked as with TX-100 or SDC. Triton X-305 was relatively ineffective, but loss of [ 3H]PGE 1 binding was greater than for PGF 2α. Increasing concentrations of dimethylsulfoxide (DMSO) progressively inhibited PGF 2α binding without affecting PGE 1 binding. The detergent, but not DMSO, induced losses of membrane PG binding were due to solubilization of the receptors. Greater amounts of membrane protein and phospholipids were solubilized at detergent (TX-100 and SDC) concentrations that solubilized 100% of PGE 1 receptors compared to 100% solubilization of F 2α receptors. Neither the duration of preincubation nor the amount of membrane protein chosen were responsible for differential PGE 1 and F 2α receptor losses. These differential membrane PG receptor losses raise the possibility of differences in PGE 1 and F 2α receptors association with the membrane structure.