Photo-Powered Artificial Organelles for ATP Generation and Life-Sustainment.

Adenosine triphosphate (ATP) is the most important immediate energy source for driving intracellular biochemical reactions in nearly all life forms. Controllable generation of ATP in life is still an unrealized goal. Here, thylakoid fragments are recombined with lipid molecules to synthesize a synthetic/biological hybrid proteoliposome, named highly efficient life-support intracellular opto-driven system (HELIOS) for the generation of ATP. With red light irradiation, HELIOS can improve the intracellular ATP concentration to 1.38-2.45 times in various cell lines. Moreover, it is noticed that HELIOS-mediated ATP generation can comprehensively promote cell functions such as protein synthesis and insulin secretion. At organ and individual levels, it is also proved that HELIOS can rescue a mouse heart from myocardial infarction and sustain life of fasting zebrafish Danio rerio models. The photo-powered artificial organelle can deepen our understanding of metabolism and enable the development of optical therapy that targets intracellular energy supply.

Thylakoid Containing Artificial Cells for the Inhibition Investigation of Light-Driven Electron Transfer during Photosynthesis.

The fabrication of artificial cells containing nature components is challenging. Herein we construct a thylakoid containing artificial cell (TA-cell) by forming multicompartmental structure inside giant unilamellar vesicles (GUVs) using osmotic stress. The thylakoids are selectively loaded inside each compartment in GUVs to mimic "chloroplast". The TA-cells are able to carry out photosynthesis upon light on. The TA-cells keep their 50% functionality of electron transfer for 12 days, which is twice of those of free thylakoids. Using TA-cells the inhibition of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and heavy metal ions (Hg2+, Cu2+, Cd2+, Pb2+ and Zn2+) on the electron transfer process in TA-cells is systematically investigated. Their half maximal inhibitory concentration (IC50) values are 36.23 ± 1.87, 0.02 ± 0.01, 0.42 ± 0.08, 0.82 ± 0.12, 1.97 ± 0.21, and 4.08 ± 0.18 µM, respectively. Hg2+ is the most toxic ion for the photosynthesis process among these five heavy metal ions. This biomimetic system can be expanded to study other processes during the photosynthesis. The TA-cells pave a way to fabricate more complicated nature component containing artificial cells.

Emergence of photoautotrophic minimal protocell-like supramolecular assemblies, "Jeewanu" synthesied photo chemically in an irradiated sterilised aqueous mixture of some inorganic and organic substances.

Sunlight exposed sterilised aqueous mixture of ammonium molybdate, diammonium hydrogen phosphate, biological minerals and formaldehyde showed photochemical formation of self-sustaining biomimetic protocell-like supramolecular assemblies "Jeewanu" (Bahadur and Ranganayaki J Brit Interplanet Soc 23:813-829 1970). The structural and functional characteristics of Jeewanu suggests that in possible prebiotic atmosphere photosy nergistic collaboration of non-linear processes at mesoscopic level established autocatalytic pathways on mineral surfaces by selforganisation and self recognition and led to emergence of similar earliest energy transducing supramolecular assemblies which might have given rise to common universal ancestor on the earth or elsewhere.