title: Physical Routes to Primitive Cells: An Experimental Model Based on the Spontaneous Entrapment of Enzymes inside Micrometer-Sized Liposomes.
abstract: How did primitive living cells originate? The formation of early cells, which were probably solute-filled vesicles capable of performing a rudimentary metabolism (and possibly self-reproduction), is still one of the big unsolved questions in origin of life. We have recently used lipid vesicles (liposomes) as primitive cell models, aiming at the study of the physical mechanisms for macromolecules encapsulation. We have reported that proteins and ribosomes can be encapsulated very efficiently, against statistical expectations, inside a small number of liposomes. Moreover the transcription-translation mixture, which realistically mimics a sort of minimal metabolic network, can be functionally reconstituted in liposomes owing to a self-concentration mechanism. Here we firstly summarize the recent advancements in this research line, highlighting how these results open a new vista on the phenomena that could have been important for the formation of functional primitive cells. Then, we present new evidences on the non-random entrapment of macromolecules (proteins, dextrans) in phospholipid vesicle, and in particular we show how enzymatic reactions can be accelerated because of the enhancement of their concentration inside liposomes.
authors: Science Department, Roma Tre University, Viale G. Marconi 446, I-00146 Rome, Italy. Alfred.Fahr@uni-jena.de.|Institut für Pharmazie, Friedrich-Schiller-Universität Jena, Lessingstraße 8, D-07743 Jena, Germany. Alfred.Fahr@uni-jena.de.
authors: Erica
authors: E
authors: D'Aguanno
authors: Science Department, Roma Tre University, Viale G. Marconi 446, I-00146 Rome, Italy. mavelli@uniba.it.|Chemistry Department, University of Bari, Via E. Orabona 4, I-70125 Bari, Italy. mavelli@uniba.it.
authors: Emiliano
authors: E
authors: Altamura
authors: Chemistry Department, University of Bari, Via E. Orabona 4, I-70125 Bari, Italy. mavelli@uniba.it.
authors: Fabio
authors: F
authors: Mavelli
authors: Institut für Pharmazie, Friedrich-Schiller-Universität Jena, Lessingstraße 8, D-07743 Jena, Germany. Alfred.Fahr@uni-jena.de.
authors: Alfred
authors: A
authors: Fahr
authors: Science Department, Roma Tre University, Viale G. Marconi 446, I-00146 Rome, Italy. pasquale.stano@uniroma3.it.
authors: Pasquale
authors: P
authors: Stano
authors: Science Department, Roma Tre University, Viale G. Marconi 446, I-00146 Rome, Italy. luisi@mat.ethz.ch.
authors: Pier Luigi
authors: PL
authors: Luisi