The role of 2-methyl-2, 4-pentanediol in sodium dodecyl sulfate micelle dissociation unveiled by dynamic light scattering and molecular dynamics simulations

The development of efficient protein refolding techniques remains a challenge in biotechnology. In that context, it has recently been reported that the addition of 2-methyl-2, 4-pentanediol (MPD) to sodium dodecyl sulfate (SDS) allows the renaturation of both soluble and membrane proteins. The present work combines experimental (dynamic light scattering; DLS) and theoretical (molecular dynamics) approaches to study the molecular basis of the association between SDS and MPD, in order to understand its relevance in the refolding process. DLS shows the micelle dissociation in the presence of molar concentrations of MPD, and simulations reveal that this process results from a screening of the negative charge on the SDS headgroup and a minimization of the solvent (water) accessibility of the detergent tail. This suggests a mechanism whereby the combination of these effects leads to the shift from a "harsh" to a "gentle" detergent behavior, which in turn promotes a productive refolding of the protein.