The two main current projects – i.e., (1) the Never Born Proteins and (2) the Minimal Cell – can generally be ascribed to the domain of Synthetic Biology. In addition, supporting research themes on the biophysics of surfactant aggregates form an integer part of the group’s activity.

NEVER BORN PROTEINS. The starting consideration of this research is that the number of proteins on earth is an infinitesimal fraction of the possible number of protein structures and the main question being how these “few” extant proteins have been selected out. Using totally random DNA sequences and using the phage display technique, a large library of “never born proteins” with an average length of 50 residues (as well as 20 residues) are being produced, a small number of them, randomly selected, are being purified and characterized. The study of their structural and biochemical properties is in progress, together with the elaboration of their meaning in terms of the biological evolution of proteins and the origin of life in general. The two main researchers in this field are Cristiano Chiarabelli and Davide de Lucrezia, as well as the students Angelica Piccolomini e Luciana Tamburrino.

THE MINIMAL CELL. The general goals of this research is the construction of vesicle-based bioreactors that simulate the main functions of biological cells. The main technique here is the introduction of genes and enzymes into vesicles. The final goal is the construction of a vesicular system that contain the minimal and sufficient number of genes and other components to be defined as living (self-sustaining + self-reproduction + evolvability). The main researchers in this filed are Pasquale Stano and Giovanni Murtas, as well as Yutetsu Kumura from the Tokyo University (from the group of prof. Ueda, with whom we are collaborating).

SUPPORTING PROJECTS ON LIPOSOMES AND OTHER COMPARTMENTS

Fusion of Vesicles: the real fusion of vesicles with different content in the water pool is the basis for the construction of vesicles having a high degree of internal complexity. This is studied using vesicles oppositely charged (e.g. oleate vs. DDAB vesicles), with all needed physical chemistry (phase diagrams and check of the fusion efficiency by fluorescence techniques). Filippo Caschera is presently working in the area.

Characterization of Phosphatidic Acid Liposomes: phosphatidic acid is the biochemical intermediate to the biosynthesis of lecithin, and in one of our projects for the minimal cells was important to see whether the corresponding liposomes are endowed with sufficient stability and capability as bioreactors. Julien Dubois has been working with this project.

Study of “Bola” Bicarboxylic Acid Systems as Possible Prebiotic Membrane-Forming Compounds: in the group of Sandra Pizzarello, at the Arizona State University, with whom we collaborate, long chain a-w dicarboxylic acids have been found in meteorites-and therefore can be considered as prebiotic surfactants. The study of their capability of forming aggregates is in progress, Chris Thomas is presently studying this together with the student Armando Romani.

Interaction of Vesicles with RNA: Chris Thomas as part of his work for the doctorate has been studying the interaction of t-RNA with vesicles, to see whether RNA is capable of discriminating the vesicle size.