SIMPLE PURIFICATION METHOD OF THE ANTIPHOSPHOLIPID ANTIBODY FROM NORMAL HUMAN PLASMA

We have reported that rabbit serum contains a phospholipid (PL)/gangli oside-binding protein which adsorbs to Sephacryl S-400 gel and aggluti nates human red blood cells. A new protein similar to the PL/gangliosi de-binding protein was simply purified from normal human plasma using Sephacryl S-400, Sepharose CL-4B and DEAE-Sepharose CL-6B columns. The purified protein was found to agglutinate rabbit red blood cells. The hemagglutination was specifically inhibited by two FL, phosphatidylse rine and phosphatidylinositol, but not by any other FL, gangliosides, saccharides or glycoproteins tested. From analyses of the N-terminal a mino acid sequence and immunological specificity, the protein was iden tified to be a human immunoglobulin M.