Peptide glue put RNA and membrane together: Origin of Life

Cooperative interactions between RNA and vesicle membranes on the prebiotic earth may have led to the emergence of primitive cells. The membrane surface offers a potential platform for the catalysis of reactions involving RNA, but this scenario relies upon the existence of a simple mechanism by which RNA could become associated with protocell membranes. Researchers from Massachusetts General Hospital recently show that electrostatic interactions provided by short, basic, amphipathic peptides can be harnessed to drive RNA binding to both zwitterionic phospholipid and anionic fatty acid membranes. They show that the association of cationic molecules with phospholipid vesicles can enhance the local positive charge on a membrane and attract RNA polynucleotides. This phenomenon can be reproduced with amphipathic peptides as short as three amino acids. Finally, they show that peptides can cross bilayer membranes to localize encapsulated RNA. This mechanism of polynucleotide confinement could have been important for primitive cellular evolution.