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Updated: Aug 8, 2026

High-throughput Crystallization of Membrane Proteins Using the Lipidic Bicelle Method
Published on: January 9, 2012
Detergent-phospholipid mixed micelles with a crystalline phospholipid core
S S Funari1, B Nuscher, G Rapp
1Max Planck Institute for Colloid and Interface Science, Golm/Potsdam, c/o Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany.
Researchers discovered unusual mixed micelles formed from detergents and phospholipids. Cooling these mixtures induces structural changes, revealing ordered acyl chains within discoidal phospholipid aggregates surrounded by detergent hoops.
Area of Science:
- Biophysics
- Materials Science
- Physical Chemistry
Background:
- Nonionic detergents and phospholipids form complex structures in aqueous solutions.
- Structural transitions in these mixtures are influenced by temperature and component ratios.
- Understanding micelle formation is crucial for drug delivery and biomembrane studies.
Purpose of the Study:
- To investigate the structural characteristics of unusual mixed micelles formed by octaethyleneglycol-mono-n-dodecylether and specific phospholipids.
- To elucidate the role of phospholipid acyl chain ordering in these mixed micellar structures.
- To develop a model explaining the observed structural and thermodynamic properties.
Main Methods:
- Synchrotron X-ray scattering to analyze micellar particle structure.
- Differential Scanning Calorimetry (DSC) to study thermal transitions and chain melting.
- Isothermal Titration Calorimetry (ITC) to quantify heat changes during component mixing.
- High-resolution Nuclear Magnetic Resonance (NMR) spectroscopy for molecular insights.
Main Results:
- Formation of mixed micelles upon cooling through phospholipid chain-melting temperatures.
- X-ray scattering revealed ordered hydrocarbon chains within micelles but no long-range order.
- Calorimetry confirmed the presence of ordered phospholipid acyl chains and heat uptake associated with gel-state phospholipids.
- A geometric model proposed discoidal phospholipid aggregates with ordered chains within a detergent hoop.
Conclusions:
- A novel micellar structure was identified in detergent-phospholipid mixtures.
- Phospholipid acyl chain ordering is a key feature of these mixed micelles.
- The detergent/phospholipid ratio influences the degree of acyl chain ordering and micellar structure.
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