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Maintenance and mobility of hemoglobin and water within the human erythrocyte after detergent disruption of the plasma membrane
Author(s) -
Cameron Ivan L.,
Cox Laura A.,
Liu Xi Rong,
Fullerton Gary D.
Publication year - 1991
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041490303
Subject(s) - chemistry , hemoglobin , membrane , biophysics , erythrocyte deformability , centrifugation , saline , red blood cell , proton , differential centrifugation , biochemistry , chromatography , biology , endocrinology , physics , quantum mechanics
Abstract Is an intact plasma membrane responsible for keeping hemoglobin and water within the human erythrocyte? If not, what is responsible? How free is Hb to move about within the erythrocyte? To answer these questions erythrocytes were taken for phase contrast microscopy, transmission electron microscopy (TEM), determination of water‐holding capacity, and proton NMR studies both before and after membrane disruption with a nonionic detergent (Brij 58). Addition of 0.2% Brij to a D 2 O saline solution of hemoglobin (Hb) caused particles of Hb to appear and to aggregate. This aggregation of Hb caused the amplitude of the Hb proton NMR spectra to decrease. Thus, the less mobile the Hb the lower the Hb proton spectra amplitude. Erythrocytes washed in D 2 O saline showed proton NMR spectra of relatively low amplitude. Addition of Brij (0.2%) to these erythrocytes caused increased Hb mobility within these erythrocytes. The TEM of fixed and thin‐sectioned erythrocytes treated with Brij showed disruption of the plasma membrane of all erythrocytes regardless of whether or not they had lost Hb. Brij‐permeabilized erythrocytes washed in D 2 O saline or in a D 2 O K buffer maintained a higher heavy water‐holding capacity upon centrifugation as compared to nonpermeabilized erythrocytes. The TEM of Brij‐treated and washed erythrocyte “shells” revealed a continuous submembrane lamina but no other evidence of cytoskeletal elements. The water‐holding capacity of the erythrocyte can be accounted for by the water‐holding capacity of hemoglobin. The evidence favors a relatively immobile state of Hb and of water in the erythrocyte that is not immediately dependent on an intact plasma membrane but is attributed to interactions between Hb molecules and the submembrane lamina.