Neutral serine proteinase and metalloproteinase strongly bound to human erythrocyte membrane.

Human and bovine erythrocyte ghosts contain a proteolytic system strongly related to membranes. Two proteinases were isolated from human erythrocyte ghosts depleted in most peripheral proteins by extraction with Triton X-100, chromatography on DEAE-cellulose and preparative electrophoresis (SDS-PAGE). The enzymes which were strongly bound to membrane serine proteinase (relative molecular weight 23 kD) and metalloproteinase (28 kD), are probably the integral membrane proteins.