The fusion of membranes in biology – necessary for endo- and exocytosis, intracellular trafficking and cell signalling – displays natures sophisticated control over nanoscale objects and sub-attolitre volumes. While Nature depends on a complex protein machinery to drive membrane fusion,1 it has been shown, that synthetic nucleic acids bearing lipophilic membrane-anchors can also mediate this process.2-4 Such lipid-modified nucleic acids (LiNAs) feature programmability in membrane fusion based on the hybridization of complementary sequences. LiNAs have the potential to allow programmed chemical syntheses within liposomes or studying enzymatic processes under highly controlled conditions. We contribute optimized LiNA-designs and conditions to achieve efficient fusion and content mixing (without significant leakage) to overcome limitations in previously reported systems and allow a broader applicability and accessibility4 of DNA-mediated liposome fusion (Figure 1). Screening of LiNAs with different membrane anchoring units and spacer lengths as well as locked nucleic acid modifications revealed candidates with improved fusion efficiency. The 17-nt recognition sequence used for all LiNAs, with a Tm of 58 °C, allowed liposome fusion at elevated temperatures up to 50 °C. A significant increase in fusion efficiency at and above physiological temperatures was observed, while leakage of liposome contents remained low. Liposome fusion induced by complementary LiNAs increased both in lipid mixing and content mixing assays (to up to 70% at 50 °C) while no fusion was observed in non-complementary controls. During fusion, leakage remained around 5% even at 50 °C, which is lower than the background leakage in absence of LiNAs. Our LiNA platform will be applied to liposome-hosted fusion-triggered chemical reactions in upcoming work.
|Status||Udgivet - sep. 2017|
|Begivenhed||Nucleic acids Chemistry & Biology 7th Cambridge Symposium - Queen's College, University of Cambridge, Cambridge, Storbritannien|
Varighed: 3. sep. 2017 → 6. sep. 2017
|Konference||Nucleic acids Chemistry & Biology 7th Cambridge Symposium|
|Lokation||Queen's College, University of Cambridge|
|Periode||03/09/2017 → 06/09/2017|