Insulin degradation-in human erythrocytes. Effect of Triton X-100 treatment on insulin-degrading activity of membranes

Human erythrocyte membrane has been demonstrate to possess an insulin-degrading activity. This activity is not due to a contamination by cytosolic factors and seems to be specific toward insulin. The fractionation of the erythrocyte membrane by Triton X-100 leads to the appraisal of an insulin-degrading activity in the Triton-extracted membranes higher than that present in the solubilized protein fraction. The degrading activity found in the extracted membranes is inhibited by the addition of the solubilized material. This last fraction seems to modulate, in the intact membrane, the whole insulin-degrading system.