Nonenzymatic glycosylation of erythrocyte membrane proteins. Relevance to diabetes
UMass Chan AffiliationsDepartment of Medicine, Division of Rheumatology
Document TypeJournal Article
In Vitro Techniques
Amino Acids, Peptides, and Proteins
Cellular and Molecular Physiology
Endocrinology, Diabetes, and Metabolism
Hemic and Lymphatic Diseases
Nutritional and Metabolic Diseases
MetadataShow full item record
AbstractNonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential labeling. Erythrocyte membranes from three patients with hemolytic anemia showed reduced incorporation of tritium from [3H]-borohydride, indicating decreased nonenzymatic glycosylation. Two patients with diabetes and hemolytic anemia had incorporation of radioactivity similar to that of normal individuals. In these groups of patients the incorporation of tritium into erythrocyte membrane proteins correlated with levels of hemoglobin AIc. Thus the modification of membrane proteins like that of hemoglobin depends on blood glucose levels as well as erythrocyte age. These studies show that the enhanced nonenzymatic glycosylation of proteins in diabetics extends beyond hemoglobin to the proteins of the erythrocyte membrane and probably affects other proteins that have slow turnover and are exposed to high concentrations of glucose.
SourceJ Clin Invest. 1980 Apr;65(4):896-901. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/48754
At the time of publication, Ellen Gravallese was not yet affiliated with the University of Massachusetts Medical School.
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