Heat Denaturation of Human Serum Albumin. Migration of Bound Fatty Acids

Abstract

Prolonged heat treatment of solutions of human serum albumin at 60°C resulted in formation of one aggregate fraction and one fraction that was stable against further heat treatment. Fatty acid analyses on these fractions indicate that the heat stable fraction is formed by migration of fatty acids from the aggregating molecules to the remaining monomer thereby stabilizing the latter against heat denaturation. Disulphide and SH groups are involved in the aggregation process.

Cell culture models of fatty acid overload: Problems and solutions

“…Thus, over-heating must be carefully avoided. It is worth highlighting that defatted or FA-free BSA is more sensitive to heat denaturation, whereas presence of FAs in BSA stabilizes BSA from heat denaturation [108].…”

Explanation of inconsistencies in the determination of human serum albumin thermal stability

“…Role of fatty acids in thermal stability of human serum albumin. The stabilization effect of bound FAs on the thermal stability of HSA has been shown previously [69][70][71][72]. Brandt and Andersson suggested FAs migration from the aggregating molecules to the remaining monomers and thereby stabilizes the latter against heat denaturation [69].…”

“…The stabilization effect of bound FAs on the thermal stability of HSA has been shown previously [69][70][71][72]. Brandt and Andersson suggested FAs migration from the aggregating molecules to the remaining monomers and thereby stabilizes the latter against heat denaturation [69]. Later Shrake and Ross concluded that biphasic thermal denaturation of HSAFA is due to FAs redistribution during denaturation process [73].…”

Quantitative Cross-Species Comparison of Serum Albumin Binding of Per- and Polyfluoroalkyl Substances from Five Structural Classes

“…With increasing PFOS concentrations, the proportion of BSA melting at the baseline ligand-free melting temperature decreased, and the remaining proportion of BSA melting at an elevated temperature increased. Biphasic denaturation profiles were also observed in differential scanning calorimetry experiments measuring BSA binding of surfactants (sodium dodecyl sulfate and a dirhamnolipid biosurfactant) (Giancola et al 1997;Deep and Ahluwalia 2001;Sánchez et al 2008), and for HSA binding of palmitic acid (Brandt and Andersson 1976;Shrake and Ross 1988;Nemergut et al 2023). While several hypotheses have been proposed, there is no clear consensus as to the cause of biphasic melt curves across protein-ligand affinity studies (Shrake and Ross 1988;Giancola et al 1997;Luan et al 2014;Nemergut et al 2023).…”