Abstract: This invention provides an antibody having antigen binding activity and which has a heavy chain constant region into which has been introduced an RGDS amino acid sequence giving the antibody affinity for cells, including macrophages. The antibody exhibits artificial cell adhesive activity which is the newly expressed activity that results from insertion of the RGDS amino acid sequence. This antibody having artificial cell adhesive activity can accelerate the phagocytosis of macrophages, and can activate other effector cells. Therefore, this antibody contributes to the self-defense mechanism.

Abstract: An onco-developmentally regulated .alpha.-N-acetylgalactosaminyltransferase isolated as a component of a particulate membrane fraction separated from cell and tissue homogenates and having the following characteristics:(a) Activity in Various Cells and Tissues--present in human fetal lung fibroblasts, hepatoma tissues and placenta, but absent from normal adult liver, lung, kidney and spleen tissues;(b) Substrate Specificity--acts on polypeptides comprising a sequence val-thr-his-pro-gly-tyr by catalyzing u-N-acetylgalactosaminylation at the thr residue of the sequence;(c) Requirements for Metal Ion--requires metal ion for activity in 25 mM tris buffer, pH 7.6;(d) Optimal pH--optimal pH is about 7.6 assayed in hepatoma cell homogenate in tris buffer and at a pH of about 6 to about 7 assayed in hepatoma cell homogenate enzyme activity is higher in 2(N-morpholino)ethanesulfonic acid than in cacodylate buffer; and(e) Km--apparent Km for UDP - GalNAc is about 48 .mu.M.