TRANSPORT OF PROTEINS DISSOLVED IN ORGANIC-SOLVENTS ACROSS BIOMIMETICMEMBRANES

Using lipid-impregnated porous cellulose membranes as biomimetic barri ers, we tested the hypothesis that to afford effective transmembrane t ransfer of proteins and nucleic acids, the vehicle solvent should be a ble to dissolve both the biopolymers and the lipids. While the majorit y of solvents dissolve one or the other, ethanol and methanol were fou nd to dissolve both, especially if the protein had been lyophilized fr om an aqueous solution of a pH remote from the protein's isoelectric p oint. A number of proteins, as well as RNA and DNA, dissolved in these alcohols readily crossed the lipidized membranes,whereas the same bio polymers placed in nondissolving solvents (e.g., hexane and ethyl acet ate) or in those unable to dissolve lipids (e.g., water and dimethyl s ulfoxide) exhibited little transmembrane transport. The solubility pf biopolymers in ethanol and methanol was further enhanced by complexati on with detergents and poly(ethylene glycol); significant protein and nucleic acid transport through the lipidized membranes was observed fr om these solvents but not from water.