Date of Original Version
Incubation of purified human serum albumin with D-[1-14C]galactose (5 mM) or D-[1-14C]glucose (5 mM) in vitro for 7 days under physiological conditions resulted in the time-dependent accumulation of radioactivity into trichloroacetic acid-precipitable material. Comparative studies indicated that the rate of sugar incorporation into albumin increased with increasing pH and temperature of incubation and followed a first order dependence with regard to monosaccharide and albumin concentrations. The extent of nonenzymatic galactosylation of human albumin was approximately 300% greater than the extent of nonenzymatic glucosylation under equivalent experimental conditions. Prolonged dialysis of the modified albumins against a large excess of the unlabeled monosaccharides failed to alter the amount of protein-bound radiolabeled carbohydrate, suggesting that the linkage between sugar and albumin is covalent in nature. The post-translational modification of proteins by nonenzymatic galactosylation may be of physiological significance in individuals with reduced galactokinase or galactose-1-phosphate uridyl transferase activities.
Urbanowski, J. C., Cohenford, M. A., & Dain, J. A. (1982). Nonenzymatic Galactosylation of Human Serum Albumin. In Vitro Preparatio. Journal of Biological Chemistry, 257(1), 111-115. Retrieved from http://www.jbc.org/content/257/1/111.
Available at: http://www.jbc.org/content/257/1/111