Delipidation of the phosphatidylcholine exchange protein from beef liver by detergents

Abstract

1. 1. A method is described to introduce [14C]phosphatidylcholine into the phosphatidylcholine exchange protein from beef liver. The effects of various detergents on this 14C-labelled phospholipid · protein complex are considered.

2. 2. As shown by spectrophotometric and radioactivity analysis of polyacrylamide gels, sodium deoxycholate, Triton X-100, lysophosphatidylcholine and sodium dodecyl sulfate delipidate the exchange protein, while mixed phosphatidylcholine-detergents micelles are formed.

3. 3. Protein delipidated by sodium deoxycholate, Triton X-100 and lysophosphatidylcholine retains its ability to catalyze the transfer of phosphatidylcholine between membranes. The immunological properties are similar to those of native protein as shown by double immunodiffusion in agar against an antiserum γ-globulin fraction.

4. 4. Sodium dodecyl sulfate and cetyltrimethylammonium bromide interact very strongly with the protein conferring their charge to the complex and destroying the antigenic determinants.