title: Bolaamphiphile-class surfactants can stabilize and support the function of solubilized integral membrane proteins.
abstract: Bolaamphiphile-class surfactants composed of two hydrophilic (maltoside) headgroups connected by long saturated alkyl chains were tested for their ability to stabilize a solubilized membrane protein, Escherichia coli diacylglycerol kinase (DAGK), and to sustain its native function. Members of this "Bis-MALT-C(18-28)" series were poor solubilizers of DAGK in the absence of conventional detergent. However, mixed micelles of the bolaamphiphiles with either dodecylphosphocholine or beta-n-decyl maltoside were more effective and enhanced DAGK's thermal stability relative to corresponding detergent-only conditions. Moreover, certain bolaamphiphiles were seen to be lipidlike by providing partial activation of DAGK's catalytic activity. Finally, addition of bolaamphiphiles to micellar NMR samples of DAGK did not result in a degradation of spectral quality, indicating their compatibility with high-resolution structural studies. To the best of our knowledge, this work represents the first documentation of the potential of bolaamphiphile-class surfactants for use in biochemical and biophysical studies of MPs.
authors.affiliation: Department of Biochemistry and Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8725, USA.
authors.forename: Qingxin
authors.initials: Q
authors.lastname: Li
authors.forename: Ritesh
authors.initials: R
authors.lastname: Mittal
authors.forename: Lijun
authors.initials: L
authors.lastname: Huang
authors.forename: Benjamin
authors.initials: B
authors.lastname: Travis
authors.forename: Charles R
authors.initials: CR
authors.lastname: Sanders
mesh_terms: D019852:Diacylglycerol Kinase / Q000737:chemistry* / Q000502:physiology; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000502:physiology; D005663:Furans / Q000737:chemistry* / Q000145:classification*; D008565:Membrane Proteins / Q000737:chemistry* / Q000502:physiology; D008823:Micelles; D055550:Protein Stability; D011728:Pyridones / Q000737:chemistry* / Q000145:classification*; D012995:Solubility; D012996:Solutions; D013501:Surface-Active Agents / Q000737:chemistry* / Q000145:classification*; D013816:Thermodynamics
chemical_list: D029968:Escherichia coli Proteins; D005663:Furans; D008565:Membrane Proteins; D008823:Micelles; D011728:Pyridones; D012996:Solutions; D013501:Surface-Active Agents; C543575:bolaamphiphile; D019852:Diacylglycerol Kinase