Formamide - based prebiotic chemistry is a set of hypotheses that predict that formamide played a large role in the process of the origin of life , providing components for the onset of both genetic and metabolic processes. [1] [2]
Formamide ( ) is the simplest natural amide containing all the elements ( carbon , oxygen , nitrogen , hydrogen ) necessary for the synthesis of biomolecules . Formamide is a very common substance in the Universe ; it was discovered in the center of galaxies [3] , in the interstellar medium [4] [5] , in star-forming molecular clouds of the galactic habitable zone [6] , including near the forming sun-like star [7 ] , and comets [8] .
Content
- 1 Sources of formamide on early Earth
- 1.1 Cyano-formaldehyde rains
- 1.2 Zinc world
- 1.3 Cosmic Origin
- 2 Formamide as a raw material for the synthesis of biomolecules
- 3 Formamide as a medium for the formation of RNA molecules
- 3.1 nucleotide formation
- 3.2 Stabilization and polymerization of RNA
- 4 References
Sources of Formamide on the Early Earth
Cyano Formaldehyde Rains
One of the hypothetical sources of formamide could be cyano-formaldehyde rains, which supposedly occurred on ancient Earth. [9] [10] In this case, during serpentinization reactions that occur when water reacts with iron silicates, which occurs when water enters the basalt cracks, forming hydrogen : [9] [10] . Further, hydrogen reduces carbon dioxide (the content of which on the ancient Earth, before the appearance of photosynthesis, was very high [11] ), giving methane ( ) and formic acid . Under the influence of solar radiation in the presence of nitrogen , methane photolysis occurs, hydrocyanic acid ( ) and its derivatives - cyanamide ( ) and cyanoacetylene ( ) Similar reactions occur in the atmosphere of modern Titan . Hydrocyanic acid (which can also be a raw material for the synthesis of RNA nucleotides, amino acids, and lipid precursors [9] [12] [13] [14] [15] [16] ) then reacts with water to obtain formamide: .
Zinc World
According to another hypothesis, the source of formamide was Zinc World (a geothermal source with a high content of potassium , phosphorus , zinc sulfide , and hydrogen sulfide , which was most likely the origin of life [9] [17] ). In the “zinc world” nitrogen, under the influence of ultraviolet radiation , on zinc sulfide crystals was reduced to ammonia [18] : , and carbon dioxide to formic acid: . Formic acid reacts with ammonia when heated, forming ammonium formate , which, when heated, decomposes to formamide and water. Due to its high boiling point (218 ° C at normal pressure), it effectively accumulates in drying puddles (geothermal springs).
Cosmic Origin
Also, some scientists suggest that formamide on Earth could have a cosmic origin, falling on the planet with a comet, meteorite or dusty disk gas . [19]
It is worth emphasizing that these hypotheses are not mutually exclusive, on the ancient Earth all 3 processes could occur simultaneously, which does not contradict the hypotheses.
Formamide as a raw material for the synthesis of biomolecules
Formamide itself is a good precursor to biomolecules. The high yield yields of formamide are nitrogen bases [20] [21] [22] [23] [24] [25] [26] , amino acids [24] [25] , sugars [24] and nucleosides [24] [9 ] [26] .
All four nitrogenous base RNAs ( adenine , cytosine , guanine and uracil ) are formed in high yield from formamide ( ) on the surface of particles of titanium oxide TiO 2 under ultraviolet radiation; adenine , cytosine, and uracil - on the surface of clay or iron oxides upon heating [9] .
Proton irradiation produces adenine , cytosine , thymine, and uracil (all thymine feeds are precursors of nucleotide RNAs ), as well as amino acids and sugars [27] .
Under ordinary conditions (in water), nitrogenous bases are not able to bind to ribose ; therefore, nucleosides do not form in an aqueous medium [9] [28] . However, by-products of formamide reactions can be, along with adenine, guanine, cytosine and uracil, their formyl derivatives having an aldehyde (CHO) group on one of the nitrogen atoms in the ring. Under the conditions of Butlerov’s reaction , ribose is being “completed” on the aldehyde group; as a result, all 4 nucleoside RNAs are formed ( adenosine , guanosine, uridine, and cytidine ) [28] [29] .
3 standard α-amino acids are obtained from formamide: glycine , alanine and proline (as well as amino acids not found in living cells, for example: methylalanine and N-formylglycine) [24] . (The synthesis of amino acids apparently follows the Strecker mechanism ) [27] .
Sugars formed from formamide are mainly pentoses ( ribose and 2'- deoxyribose ) and hexoses ( glucose , lactose , manose ) [24] .
In addition, hydrocyanic acid , which can be both a precursor of formamide and its decomposition product (Under the action of dehydrating agents ( P 2 O 5 , etc.), formamide is dehydrated to form hydrocyanic acid : ) is also a raw material for the synthesis of biomolecules [30] .
Previously, hydrocyanic acid, as one of the products formed in the Miller flask , was only capable of forming amino acids [31] [32] . Now, more complex reactions are discovered, for example, cyanosulfide protometabolism discovered by John Sutherland , during which the following are formed: cytosine RNA nucleotides and (under UV irradiation) uracil, 11 amino acids ( glycine , alanine , serine , threonine , glutamine , glutamic acid , asparagine , aspartic acid , proline , arginine and valine ) and lipid precursors [12] [33] [34] . And also the reaction discovered by Thomas Carell, in which hydrogen cyanide and formamide are the starting materials for the synthesis of a huge number of different types of nucleosides [15] [16] (However, with UV irradiation, only 4 nucleotides remain [9] [35] [36] [ 25] : adenine, guanine, cytosine, uracil, ie, "building blocks" of RNA).
Thus, from formamide and hydrocyanic acid you can get all the necessary “ingredients” to launch the “ RNA world ”, which is a key moment in the origin of life, starting the Darwinian evolution process [37] [26] .
Formamide as a medium for the formation of RNA molecules
Nucleotide Formation
Phosphorylation of nucleosides in an aqueous medium is an extremely inefficient process. Moreover, the formation of nucleotides is necessary for the onset of abiogenesis , because without nucleotides the construction of RNA is impossible. But in the aqueous formamide medium, phosphorylation occurs already at a sufficient rate [9] [38] [39] [40] . Only the most common phosphate mineral, hydroxylapatite Ca5 (PO4) 3OH, a few copper salts and heating to 80 ° C are needed. Copper is also used for phosphorylation of nucleosides in modern cells; it is a part of the purine nucleoside kinase enzyme [9] . Thus, the model of the "formamide world" solves the problem of nucleotide synthesis.
RNA stabilization and polymerization
An aqueous solution, as a medium for the appearance of life, has its drawbacks. In an aqueous medium, proteins, RNA, and DNA are unstable [19] . Over time, these long molecules break up into separate units — amino acids or nucleotides. The chemical combination of amino acids into protein or nucleotides in RNA occurs with the release of water. Therefore, when there is a lot of it around, the equilibrium of this reaction is shifted towards the breakdown of protein or RNA with the absorption of water ( hydrolysis) . [9] [41] However, this problem is solved in a water-formamide solution, where, due to the reduced water content, the reaction will be shifted not to its absorption, but to the side of excretion, so that RNA chains can form without breaking up [17] [26] [42] .
Links
- ↑ Raffaele Saladino, Giorgia Botta, Samanta Pino, Giovanna Costanzoc, Ernesto Di Mauro. Genetics first or metabolism first? The formamide clue unopened .
- ↑ Raffaele Saladino, Claudia Crestini, Samanta Pino, Giovanna Costanzo, Ernesto Di Mauro. Formamide and the origin of life . ScienceDirect .
- ↑ Gottlieb, CA; Palmer, Patrick; Rickard, LJ; Zuckerman, B. Studies of Interstellar Formamide Neopr . astrophysics data system (June 1973).
- ↑ A. Coutens, JK Jørgensen, MHD van der Wiel, HSP Müller, JM Lykke, P. Bjerkeli, TL Bourke, H. Calcutt, MN Drozdovskaya, C. Favre, EC Fayolle, RT Garrod, SK Jacobsen, NFW Ligterink, KI Öberg, MV Persson, EF van Dishoeck, SF Wampfler. The ALMA-PILS survey: First detections of deuterated formamide and deuterated isocyanic acid in the interstellar medium . Astronomy & Astrophysics (June 2016).
- ↑ Hollis, JM; Lovas, FJ; Remijan, Anthony J .; Jewell, PR; Ilyushin, VV; Kleiner, I. Detection of Acetamide (CH 3 CONH 2): The Largest Interstellar Molecule with a Peptide Bond . zenodo (May 20, 2006).
- ↑ Gilles R. Adande, Neville J. Woolf, Lucy M. Ziurys. Observations of Interstellar Formamide: Availability of a Prebiotic Precursor in the Galactic Habitable Zone . NCBI (2013 May).
- ↑ Formamide, a key molecule in the life appearance, detected in the neighborhood of a sun-like forming star . IRAM (January 29, 2013).
- ↑ Bockelée-Morvan, D .; Lis, DC; Wink, JE; Despois, D .; Crovisier, J .; Bachiller, R .; Benford, DJ; Biver, N .; Colom, P .; Davies, JK; Gérard, E .; Germain, B .; Houde, M .; Mehringer, D .; Moreno, R .; Paubert, G .; Phillips, TG; Rauer, H. New molecules found in comet C / 1995 O1 (Hale-Bopp). Investigating the link between cometary and interstellar material . Astronomy and Astrophysics (January 2000).
- ↑ 1 2 3 4 5 6 7 8 9 10 11 Mikhail Nikitin. The origin of life. From the nebula to the cell .. - 2016. - ISBN 978-5-91671-584-2 .
- ↑ 1 2 Mikhail Nikitin. The methane cycle on the ancient Earth .
- ↑ Kevin Zahnle, Laura Schaefer, Bruce Fegley. Earth's Earliest Atmospheres . NCBI (2010 Oct).
- ↑ 1 2 Elena Naimark. Cyanosulfide protometabolism is a sure way to earthly life . Elements (03.24.2015).
- ↑ Alexander Markov. Chemists have overcome the main obstacle to abiogenic RNA synthesis . Elements (05/18/2009).
- ↑ Chemists understood how RNA could have formed on early Earth . Scientific Russia (October 19, 2018).
- ↑ 1 2 Robert Service. Chemists find a recipe that may have jump-started life on Earth . Science (Oct. 18 2018).
- ↑ 1 2 Sidney Becker, Christina Schneider, Hidenori Okamura, Antony Crisp, Tynchtyk Amatov, Milan Dejmek & Thomas Carell. Wet-dry cycles enable the parallel origin of canonical and non-canonical nucleosides by continuous synthesis . Nature (11 January 2018).
- ↑ 1 2 Mikhail Nikitin. Are ground geothermal fields the cradle of life? (2016).
- ↑ Mikhail Nikitin. "Zinc world" .
- ↑ 1 2 Life arose without water? .
- ↑ SD Senanayake, H. Idriss. Photocatalysis and the origin of life: Synthesis of nucleoside bases from formamide on TiO2 (001) single surfaces . PNAS (January 31, 2006).
- ↑ Raffaele Saladino, Giorgia Botta, Michela Delfino, Ernesto Di Mauro. Meteorites as Catalysts for Prebiotic Chemistry .
- ↑ Niether, Doreen; Afanasenkau, Dzmitry; Dhont, Jan KG Accumulation of formamide in hydrothermal pores to form prebiotic nucleobases . astrophysics data system (April 2016).
- ↑ Hannah L. Barks Ragan Buckley Gregory A. Grieves Ernesto Di Mauro Nicholas V. Hud Prof. Thomas M. Orlando Prof. Guanine, Adenine, and Hypoxanthine Production in UV ‐ Irradiated Formamide Solutions: Relaxation of the Requirements for Prebiotic Purine Nucleobase Formation . ChemBioChem (07 June 2010).
- ↑ 1 2 3 4 5 6 Raffaele Saladino, Eleonora Carota, Giorgia Botta, Mikhail Kapralov, Gennady N. Timoshenko, Alexei Y. Rozanov, Eugene Krasavin, and Ernesto Di Mauroc. Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation . NCBI (2015 Apr 13).
- ↑ 1 2 3 Armen Mulkidzhanyan, Ivar Maksutov. How an ancient cell could arise from the simplest RNA aggregates is the main question for scientists . PostScience (28 NOVEMBER 2014).
- ↑ 1 2 3 4 Dr. Judit E. Šponer, Prof. Jiří Šponer, Dr. Olga Nováková, Prof. Viktor Brabec, Dr. Ondrej Šedo, Dr. Zbyněk Zdráhal, Dr. Giovanna Costanzo, Dr. Samanta Pino, Prof. Raffaele Saladino, Prof. Ernesto Di Mauro. Emergence of the First Catalytic Oligonucleotides in a Formamide ‐ Based Origin Scenario . Chemistry a european journal (January 25, 2016).
- ↑ 1 2 Raffaele Saladino, Eleonora Carota, Giorgia Botta, Mikhail Kapralov, Gennady N. Timoshenko, Alexei Y. Rozanov, Eugene Krasavin, and Ernesto Di Mauro. Meteorite-catalyzed syntheses of nucleosides and of other prebiotic compounds from formamide under proton irradiation . PNAS (May 26, 2015).
- ↑ 1 2 Mikhail Nikitin. Obtaining nucleotides (2016).
- ↑ The appearance of nucleotides. The development of life on Earth - 6 .
- ↑ Rutten M. Oro experiments with a heated aqueous medium (1971).
- ↑ Stanley Miller. A production of amino acids under possible primitive Earth conditions (1953).
- ↑ PZ Myers. Old scientists never clean out their refrigerators (2008).
- ↑ Bhavesh H. Patel, Claudia Percivalle, Dougal J. Ritson, Colm D. Duffy & John D. Sutherland. Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism . Nature (2015).
- ↑ Bhavesh H. Patel, Claudia Percivalle, Dougal J. Ritson, Colm D. Duffy and John D. Sutherland. [ https://earthscience.rice.edu/wp-content/uploads/2015/10/Nature-Chemistry-2015-Patel.pdf Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism] . Nature (2015).
- ↑ Mikhail Nikitin. Sun: friend or foe? (2016).
- ↑ Armen Y. Mulkidjanian, Michael Y. Galperin. Physico-Chemical and Evolutionary Constraints for the Formation and Selection of First Biopolymers: Towards the Consensus Paradigm of the Abiogenic Origin of Life . Chemistry & biodiversity (21 September 2007).
- ↑ Alexander Markov. In search of the beginning of evolution . Elements (2015).
- ↑ Mikhail Nikitin. Ribozymes master metabolism (2016).
- ↑ Giovanna Costanzo, Raffaele Saladino, Claudia Crestini, Fabiana Ciciriello and Ernesto Di Mauro. Nucleoside Phosphorylation by Phosphate Minerals . Journal of biological chemistry (April 3, 2007.).
- ↑ Allen M. Schoffstall. Prebiotic phosphorylation of nucleosides in formamide (December 1976).
- ↑ Mikhail Nikitin. How much water is needed for the appearance of life? .
- ↑ Dr. Giovanna Costanzo Prof. Raffaele Saladino Dr. Giorgia Botta Dr. Alessandra Giorgi Dr. Anita Scipioni Dr. Samanta Pino Prof. Ernesto Di Mauro. https://onlinelibrary.wiley.com/doi/abs/10.1002/cbic.201200068 . ChemBioChem (March 30, 2012).