A theoretical analysis of the multiple binding of palmitate by bovine serum albumin: The relationship to uptake of free fatty acids by tissues

Abstract

The distribution of palmitate between the palmitate bound to serum albumin and the free form in plasma was calculated by use of a computer program and published association constants and binding capacities. The analysis was carried out for molar ratios of palmitate to albumin of 0.5, 1, 2, 3 and 4. Over this range only 0.0051% to 0.049% of the palmitate would be in the unbound form. The program also provided computed values for the quantitative distribution of palmitate among the eight binding sites on the protein. Computations showed that at low molar ratios the high affinity sites would bind most of the fatty acid, but as the molar ratio increased the sites with intermediate association constants would assume a greater role in the binding. The relative role of each site in the transport of palmitate to tissues was found to differ markedly at low molar ratios compared with high molar ratios. At low molar ratios the high affinity sites would be the main contributors of the palmitate, however, at high molar ratios the sites with intermediate affinities would be the main contributors. The physiological and pharmacological implications of the results are discussed.