Abstract EANA2026-41

Abstract

 Proteinoid microspheres are spherical micro-sized structures formed by the spontaneous aggregation of amino acid polymers or their precursors (proteinoids). Given that the amino acids constituting proteinoid microspheres have been discovered in meteorites and that these structures incorporate organic matter during aggregation, they may have been utilized by primitive life forms. This study aimed to achieve functional expression by fusing proteinoid microspheres with nucleic acids. Plasmid DNA encoding the gene for green fluorescent protein (GFP) was taken up by proteinoid microspheres, and the transformation of both E. coli and animal cells was investigated.

  Proteinoids were synthesized by heating monoammonium malate. The proteinoid microsphere suspension was dissolved in hot water and allowed to cool to room temperature. Then, a plasmid solution was added to the proteinoid microsphere suspension, which was then heated and cooled to room temperature, allowed to reaggregate.

  A plasmid-containing microsphere suspension was mixed with an E. coli (HB101) suspension and cultured on agar medium. Subsequently, fluorescence was observed using UV irradiation and a fluorescence microscope. A similar experiment was conducted using Human Embryonic Kidney cells 293 (HEK293) cells.

 When plasmid-containing proteinoid microspheres were added to E. coli, and the bacteria proliferated. Observation of the proliferated E. coli revealed a green fluorescent protein encoded by the plasmid DNA. Experiments were conducted by varying the amount of proteinoid microspheres and the presence or absence of metal ions, but no clear differences were observed. No fluorescence was observed in the mammalian cell experiment. However, because the extracted DNA from transformed cells could be amplified by PCR, the presence the DNA inside the cells was confirmed. This indicates that while the GFP gene was successfully transformed using the microspheres, gene expression did not occur due to some unknown factor. When experiments were conducted by varying the ratio of proteinoid microsphere suspension to plasmid DNA, PCR bands were observed only at a 2:1 ratio.

 This study suggests that proteinoid microspheres can fuse with other functional polymers while retaining their functionality and that other cells can take up proteinoid microspheres. Furthermore, the fusion of proteins and nucleic acids is essential for the origin of life, we have demonstrated that plasmid microspheres can serve as carriers for nucleic acids. This implies that proteinoid microspheres may have affected in the evolutionary process leading to primitive life.