Stability of acetaldehyde fractions with various hemoglobin fractions.

The stabilities of 14C-acetaldehyde with various hemoglobin fractions (HbA1a + b, HbA1a, and HbA0) were examined by determining amounts of adducts remaining after dialysis at 4 degrees C for various time intervals. Significant differences were found in the stabilities of adducts formed with various hemoglobin fractions. Acetaldehyde adducts formed with HbA1a + b were more stable to dialysis than adducts formed with HbA0 or HbA1c (7-8% of total adducts formed with HbA1a + b were stable to dialysis, compared with 4-5% stable adducts formed with either HbA0 or HbA1c). While only 37-57% of the trichloroacetic acid (TCA) precipitable adducts from HbA0 or HbA1c samples were stable to dialysis, 72-75% of TCA precipitable adducts from HbA1a + b were retained after dialysis. Posttranslational modification of hemoglobin by phosphorylated glycolytic intermediates appears to alter the physical properties of hemoglobin following further modification with acetaldehyde. In view of the increased amounts of glycosylated proteins found in patients with diabetes, these observations may be relevant to the pathogenesis of the sequelae of diabetes and/or alcoholism and the influence of one chronic illness on the other.