Abnormal Solubilization by Triton X-100 of Erythrocyte Membranes from Patients with Paroxysmal Nocturnal Hemoglobinuria 1

Abstract

Summary

Erythrocyte membranes from patients with paroxysmal nocturnal hemoglobinuria (PNH) were found to undergo a deficient degree of solubilization when reacted with the nonionic detergent Triton X-100. Upon exposure to concentrations of Triton X-100 causing partial membrane solubilization in 5 mM phosphate buffer, pH 7.4, cholesterol and hexoses from patients′ membranes dissociated to a lower degree than the membrane constituents from normal controls and patients with hemolytic anemias unrelated to PNH. The degree of solubilization of membrane protein was identical with all types of erythrocytes. The degree of hemolysis caused by Triton X-100 was similar with PNH and normal red cells. Immunoelectrophoresis of normal membranes solubilized with 1-5% Triton X-100 yielded several α-β₁ lines and one β₂ line. PNH membranes produced similar α-β₁ lines but the β₂ line was absent or very faint. Since it was known that the β₂ component of normal membranes is a glycolipoprotein with high affinity for Triton X-100, the immunoelectrophoretic abnormality of PNH erythrocyte membranes indicates an altered reactivity with Triton X-100 of this glycolipoprotein membrane component. The findings suggest that in PNH there is a major defect in the organization of the erythrocyte membrane constituents which is mediated by an as yet undefined anomaly in the membrane β₂ glycolipoprotein.