THE POTENTIAL OF FLUORINATED SURFACTANTS IN MEMBRANE BIOCHEMISTRY

Detergents are important reagents in membrane biochemistry. Since each membrane system studied places different demands on the detergent in terms of desirous physicochemical properties, detergents new to bioche mistry must continuously be sought. Ammonium perfluorooctanoate (APFO) was investigated, as representative of fluorinated surfactants, in te rms of its suitability as a ''biological detergent.'' It did not inter fere with the Markwell modification of the Lowry procedure at detergen t concentrations of up to 2% (w/v). Critical micellization concentrati on (cmc) values (0.013-0.0275 M) for this detergent were determined in a number of buffers of biological interest. It was demonstrated that the detergent can be removed by dialysis, albeit slowly. This slow rem oval may be particularly useful for reconstitution/crystallization stu dies. Solubilization studies on several membrane systems containing th e proteins listed (the major protein of the membrane sector of the vac uolar H+-ATPase (16 kDa protein); photosystem II; equine herpes virus (EHV) envelope proteins) indicate that it is a potent solubilizing age nt, likely to enhance the yield in cases where solubilization has alre ady been demonstrated, and, in other cases, to solubilize proteins for merly recalcitrant to solubilization. The removal of APFO from solubil ized 16-kDa protein by means of Extracti-Gel D resin as a means of exc hanging detergents quickly and with a minimum requirement for second d etergent was investigated. (C) 1995 Academic Press, Inc.