Immunochemical investigations of Rh0(D) activity detected in Band 3 of red cell membrane.

Stroma from D positive red cell was solubilized with 1% deoxycholic acid (DOC) and was applied onto Sepharose 4B and 6B, followed by fractionation with activated thiol Sepharose 4B. By this method Band 3 containing no carbohydrate was prepared. The Band 3 was incubated with human anti-D, then immune complex soluble in DOC solution was produced. This complex was not prepared from red cell components other than Band 3, nor from Band 3 from D negative red cell. The complex agglutinated papainized D positive red cells. Molecular weight of the complex was estimated to be 500,000 to 700,000 by the gel filtration method. The molecular weight increased according to the time of incubation. The complex gave a precipitation line in counter immunoelectrophoresis (IEP), a single peak in crossed IEP against anti-Band 3, and a line at gamma-globulin region in IEP against anti-human serum. SDS-polyacrylamide gel disc electrophoresis of the complex showed the pattern consisting of fragments of immunoglobulin G and Band 3 which was not stained with periodic acid Schiff reagent. These support our results that Rh-Hr blood type activities are located in Band 3 almost free of carbohydrate.