Microstructural polymorphism in bovine brain galactocerebroside and its two major subfractions

Area of Science:

• Lipid self-assembly
• Biophysical chemistry
• Materials science

Background:

• Galactocerebrosides are key lipids in brain tissue, forming structures like myelin.
• Understanding their self-assembly is crucial for comprehending lipid-related diseases and biological functions.

Purpose of the Study:

• To investigate the formation of microstructures from different galactocerebroside subfractions.
• To explore the potential of these structures as models for biological lipid assemblies.

Main Methods:

• Aqueous suspensions of galactocerebrosides and their subfractions were prepared.
• Thermal cycling in non-aqueous solvents was used to induce specific lipid self-assembly.
• Microscopy techniques were employed to characterize the resulting microstructures.

Main Results:

• Non-hydroxyacyl galactocerebrosides formed helical ribbons (approx. 100 nm diameter) upon thermal cycling.
• Alpha-hydroxyacyl galactocerebrosides and unfractionated cerebrosides formed straight needles (cochleate cylinders, approx. 100 nm diameter, variable length).
• This is the first report of quantitative formation of high axial ratio microstructures from natural lipid mixtures.

Conclusions:

• Different galactocerebroside components yield distinct crystalline microstructures.
• These synthetic structures resemble biological lipid deposits in diseases and structures like myelin.
• Galactocerebrosides may be important for stabilizing biological cylindrical structures.