Characterization of unstable hemoglobin A1c complexes by dynamic capillary isoelectric focusing.

摘要: Glucose spontaneously reacts with hemoglobin amino groups to produce unstable Schiff base complexes that can dissociate or rearrange form stable Amadori products. We used dynamic capillary isoelectric focusing and boronate affinity chromatography assess the formation dissociation of in vitro. Formation was studied by incubating erythrocytes at 37°C for up 24h phosphate-buffered saline (PBS) supplemented 0 55.6 mmol/L glucose. Dissociation glucose-loaded PBS without Dynamic separated A1c into two subfractions identified as A1c1 A1c2. The subfraction contained both complexes. A1c2 only Both quantitatively increased presence glucose decreased its absence. Rates increase decrease were faster time equilibrium shorter (~4 h) compared (~20 h). Unstable did not bind columns but instead eluted intact from nonglycated fractions. Cyanoborohydride reduction confirmed Evidence multiple different rates glycation suggests new models are needed describe nonenzymatic glycation.