Detection of Macromolecular Fractions in HCN Polymers Using Electrophoretic and Ultrafiltration Techniques

Abstract

Elucidating the origin of life involves synthetic as well as analytical challenges. Herein, for the first time, we describe the use of gel electrophoresis and ultrafiltration to fractionate HCN polymers. Since the first prebiotic synthesis of adenine by Oró, HCN polymers have gained much interest in studies on the origins of life due to the identification of biomonomers and related compounds within them. Here, we demonstrate that macromolecular fractions with electrophoretic mobility can also be detected within HCN polymers. The migration of polymers under the influence of an electric field depends not only on their sizes (one-dimensional electrophoresis) but also their different isoelectric points (two-dimensional electrophoresis, 2-DE). The same behaviour was observed for several macromolecular fractions detected in HCN polymers. Macromolecular fractions with apparent molecular weights as high as 250 kDa were detected by tricine-SDS gel electrophoresis. Cationic macromolecular fractions with apparent molecular weights as high as 140 kDa were also detected by 2-DE. The HCN polymers synthesized were fractionated by ultrafiltration. As a result, the molecular weight distributions of the macromolecular fractions detected in the HCN polymers directly depended on the synthetic conditions used to produce these polymers. The implications of these results for prebiotic chemistry will be discussed.

A Comparative Study on HCN Polymers Synthesized by Polymerization of NH4CN or Diaminomaleonitrile in Aqueous Media: New Perspectives for Prebiotic Chemistry and Materials Science

“…It is noteworthy that this temperature is lower than that previously reported, that is, a moderate temperature can also lead to DAMN polymerization. The FTIR spectra of these new insoluble DAMN polymers (Figure c and d) resembled those of the NH 4 CN polymers synthesized at low temperatures ( T ≤38 °C), as well as those of analogous NH 4 CN polymers prepared at 80 °C (Figures a and b) and other FTIR spectra of HCN polymers obtained under different experimental conditions in aqueous solutions and aprotic media, or even without solvents . These results demonstrate that NH 4 CN polymerization is a spontaneous process, whereas DAMN polymerization requires thermal activation.…”

“…DAMN might be considered ani ntermediate, but not the only one, in the polymerization of cyanide. In addition, the presence of ammonium ions eems to improve cyanide polymerization [6] or DAMN polymerization.…”

“…Other reasons for this lack of knowledge are that the final products are insoluble in water and have very poor solubility in common organic solvents. This makes all characterization methods and separation techniques that require solubility impossible, and the water‐soluble intermediates of polymerization show a broad distribution of molecular weights and highly charged structures …”

“…This makes all characterization methods and separation techniques that require solubility impossible, and the water-soluble intermediates of polymerization show ab road distribution of molecular weights and highly charged structures. [4][5][6] HCN polymers are mainly known in the fields of prebiotic chemistry,i ns tudies on the origins of life and in astrobiology, because they are considered to play key roles in the formation of the first and primeval protometabolic and informational systems [7][8][9][10] and most stable organics in space. [11] Indeed,H CN polymers may be among the organic macromolecules that are most readily formed in the solar system.…”

Glaciers and Ice Sheets As Analog Environments of Potentially Habitable Icy Worlds

“…The existence of cryovolcanism on the moon’s surface has been suggested ( Fortes et al, 2007 ). Cryovolcanism is a very important phenomenon from an astrobiological point of view, because it allows the mixing of organic molecules such as hydrocarbons, nitriles and cyanides with water, giving rise to oxidized more complex prebiotic molecules ( Neish et al, 2006 ; Marin-Yaseli et al, 2017 ). Titan appears to be very Earth-like in its geology, despite the very different surface conditions and composition.…”