The components of the hemoglobin-A 1 fraction - hemoglobins A(1a-c) - arise from nonenzymatic glycosylation of hemoglobin A at the β-chain N-terminal amino groups and can be resolved from hemoglobin A by cation exchange chromatography. Glycosylation can also occur at the α-chain N-terminals as well as the ε-amino groups of lysine residues of both α- and β-chains; this results in glycosylated species appearing in the hemoglobin-A fraction. In this study, we determined the extent of hemoglobin-A glycosylation using a colorimetric chemical method specific for the detection of ketoamine-linked hexoses in proteins. We demonstrate increased glycosylation of the main hemoglobin-A fraction in diabetic patients, which correlates significantly (r = 0.72, P < 0.001) with the hemoglobin-A 1 percentage determined by column chromatography in the corresponding hemolysates. This finding provides the basis for the application of this chemical procedure to the measurement of total glycosylation of hemoglobin.
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology, Diabetes and Metabolism