LIPOPHILIC PROTEINS EXTRACTED FROM CHICK-EMBRYO CELL-CULTURES BY DIFFERENT METHODS

Compounds containing both proteins and phospholipids were extracted by 3 different methods with organic solvents from labeled chick embryo cells cultured in vitro. The extracted material was analyzed by polyacrylamide gel electrophoresis (PAGE) and thin layer silica gel chromatography (TLC). The characteristics of these compounds are: 1. 1) Polypeptides of an apparent molecular weight comprised between 10 and 20 Kdaltons·are extracted by each of the 3 methods. Additional polypeptides of a molecular weight ranging from 20 to 70 Kdaltons are extracted with acid chloroform-methanol; with this method the highest yields are obtained. 2. 2) The phospholipid composition differs from that of the whole cell; it is enriched in phosphatidylserine and phosphatidylinositol. 3. 3) The compounds are soluble in organic solvents and in aqueous solvents containing SDS. 4. 4) Membrane enriched fractions contain more of these compounds than whole cells. © 1979.