Dodecyl-β-melibioside Detergent Micelles as a Medium for Membrane Protein's

There remains a need for new non-ionic detergents that are suitable for use in biochemical and biophysical studies of membrane proteins. Here we explore the properties of n-dodecyl-beta-melibioside (beta-DDMB) micelles as a medium for membrane proteins. Melibiose is D-galactose-alpha(1 -> 6)-D-glucose. Light scattering showed the beta-DDMB micelle to be roughly 30 kDa smaller than micelles formed by the commonly used n-dodecyl-beta-maltoside (beta-DDM). beta-DDMB stabilized diacylglycerol kinase (DAGK) against thermal inactivation. Moreover, activity assays conducted using aliquots of DAGK purified into beta-DDMB yielded activities that were 40% higher than those of DAGK purified into beta-DDM. beta-DDMB yielded similar or better TROSY-HSQC NMR spectra for two single-pass membrane proteins and the tetraspan membrane protein peripheral myelin protein 22. beta-DDMB appears be a useful addition to the toolbox of non-ionic detergents available for membrane protein research.