Purity: > 85% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 10% glycerol.. ART4, also known as ecto-ADP-ribosyltransferase 4, is a glycosylphosphatidylinositol (GPI)-linked membrane protein carrying Dombrock blood group antigens. It is developmentally regulated during erythroid differentiation and occurs at highest levels in the fetal liver. It is a member of the ADP-ribosyltransferase gene family but enzymatic activity has not been demonstrated experimentally. Recombinant human ART4, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.