The Mechanism of Vesicle Solubilization by the Detergent Sodium Dodecyl Sulfate.

ABSTRACT

Membrane solubilization by sodium dodecyl sulfate (SDS) is indispensable for many established biotechnological applications, including viral inactivation and protein extraction. Although the ensemble thermodynamics have been thoroughly explored, the underlying molecular dynamics have remained inaccessible, owing to major limitations of traditional measurement tools. Here, we integrate multiple advanced biophysical approaches to gain multiangle insight into the time-dependence and fundamental kinetic steps associated with the solubilization of single submicron sized vesicles in response to SDS. We find that the accumulation of SDS molecules on intact vesicles triggers biphasic solubilization kinetics comprising an initial vesicle expansion event followed by rapid lipid loss and micellization. Our findings support a general mechanism of detergent-induced membrane solubilization, and we expect that the framework of correlative biophysical technologies presented here will form a general platform for elucidating the complex kinetics of membrane perturbation induced by a wide variety of surfactants and disrupting agents.