Solubilization and characterization of apolipoprotein B from human serum low-density lipoprotein in n-dodecyl octaethylene glycol monoether

Abstract

Apolipoprotein B, the core polypeptide of human serum low-density lipoprotein, retains its native association state (500,000 g/complex), as well as its native conformation as judged by circular dichroism, when all lipid has been replaced by a nonionic detergent. Protein solubilized in this detergent should be well-suited for lipid binding studies. The native association state is also preserved when lipid is replaced by ionic detergents, but in this case the protein undergoes a conformational change, which can be reversed if the ionic detergent is replaced by nonionic detergent. The constancy of the state of association of the B polypeptide in a variety of amphiphilic environments contrasts with what has been observed with polypeptides from high-density lipoproteins which exist in different states of association under different conditions.