Spontaneous formation of helical structures from phospholipid-nucleoside conjugates

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Biophysical Chemistry

Background:

• Phospholipid-nucleoside conjugates are novel molecules with potential for self-assembly.
• Understanding their self-organization is crucial for designing advanced nanomaterials.
• Previous studies have explored amphiphilic molecule self-assembly, but less is known about these specific conjugates.

Purpose of the Study:

• To synthesize and characterize dimyristoyl-5 -phosphatidylnucleosides.
• To investigate the self-organization behavior and resulting morphologies of these conjugates in aqueous solutions.
• To elucidate the influence of different nucleoside bases and alkyl chain lengths on the self-assembled structures.

Main Methods:

• Enzymatic synthesis of phospholipid-nucleoside conjugates.
• Investigation of self-organization using techniques to observe morphology and physicochemical properties.
• Analysis of structures formed under varying pH conditions and with different conjugate compositions.

Main Results:

• Dimyristoyl-5 -phosphatidyladenosine (DMPA) formed multihelical strands in neutral/alkaline solutions and tubular scrolls in acidic solutions.
• Conjugates with shorter alkyl chains (DLPA, DDPA, DOPA) formed tape-like structures.
• Dimyristoyl-5 -phosphatidylcytidine (DMPC) initially formed networks then multihelical strands; Dimyristoyl-5 -phosphatidyluridine (DMPU) formed crystalline platelets.
• A DMPA:DMPU mixture created a unique hybrid helical strand with distinct dimensions.

Conclusions:

• Phospholipid-nucleoside conjugates exhibit diverse self-assembly behaviors, forming helical strands, scrolls, tapes, networks, platelets, and hybrid structures.
• The type of nucleoside group and the length of the alkyl chains significantly dictate the final morphology.
• These findings provide insights into structure-property relationships for designing functional self-assembled systems.