scholarly journals Thermodynamic Origin of Homochirality for Macromolecules in Nature

2020 ◽  
Vol 0 (0) ◽  
pp. 2011078-0
Author(s):  
Xin Xu
Keyword(s):  
Origin Of Homochirality

Homochirality as the Signature of Extra-Terrestrial Life

1997 ◽  
Vol 161 ◽  
pp. 505-510
Author(s):  
Alexandra J. MacDermott ◽  
Laurence D. Barron ◽  
Andrè Brack ◽  
Thomas Buhse ◽  
John R. Cronin ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Optical Rotation ◽  
Physical Origin ◽  
Natural Choice ◽  
Rosetta Mission ◽  
Terrestrial Life ◽  
Subsurface Layers ◽  
Solar System Bodies ◽  
Origin Of Homochirality

AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

scholarly journals Homochirality Is Originated from Handedness of Helices

2020 ◽  
Author(s):  
Shubin Liu
Keyword(s):  
Amino Acids ◽  
Asymmetric Synthesis ◽  
Electrostatic Interactions ◽  
Alpha Helix ◽  
Root Cause ◽  
Macromolecular Assembly ◽  
Nucleotide Sugars ◽  
Cooperativity Effects ◽  
Natural Amino Acids ◽  
Origin Of Homochirality

Homochirality is a common feature of amino acids and carbohydrates, whose origin is still unknown. For example, 19 of 20 natural amino acids are L-chiral but deoxyribose sugars in DNA are always D-chiral. Meanwhile, right-handed helices are ubiquitous in nature. Are these two phenomena intrinsically correlated? Here, we propose that homochirality of amino acids and nucleotide sugars is originated from the handedness of helices. We show that right-handed 3<sub>10-</sub>helix and alpha-helix favor the L-chiral form for amino acids, but for deoxyribose sugars right-handed helices prefer the D-chiral form instead. Our analyses unveil that there exist strong cooperativity effects dominated by electrostatic interactions. This work not only resolves the mystery of homochirality by providing a unified explanation for the origin of homochirality in proteins and DNA using helical secondary structures as the root cause, but also ratifies the Principle of Chirality Hierarchy, where chirality of a higher hierarchy dictates that of lower ones. Possible applications of the present work to asymmetric synthesis and macromolecular assembly are discussed.

Formation of homochiral helical nanostructures in diblock copolymers under the confinement of nanopores

2019 ◽  
Vol 21 (13) ◽  
pp. 7067-7074 ◽  
Author(s):  
Tao Yang ◽  
Haiyan Xue ◽  
Ruifang Cao ◽  
Weihua Li
Keyword(s):  
Diblock Copolymers ◽  
Helical Structures ◽  
Origin Of Homochirality

The control of the homochirality of helical structures formed in achiral systems is of great interest as it is helpful for understanding the origin of homochirality in life.

scholarly journals Achiral amino acid glycine acts as an origin of homochirality in asymmetric autocatalysis

2019 ◽  
Vol 17 (17) ◽  
pp. 4200-4203 ◽  
Author(s):  
Arimasa Matsumoto ◽  
Hanae Ozaki ◽  
Sumeru Tsuchiya ◽  
Toru Asahi ◽  
Meir Lahav ◽  
...  
Keyword(s):  
Amino Acid ◽  
Asymmetric Autocatalysis ◽  
Origin Of Chirality ◽  
Origin Of Homochirality ◽  
Amino Acid Glycine

Achiral glycine acts as the origin of chirality in conjunction with asymmetric autocatalysis to afford highly enantioenriched compound.

scholarly journals Transfer of chiral information from a chiral solvent to a two-dimensional network

2017 ◽  
Vol 204 ◽  
pp. 215-231 ◽  
Author(s):  
Iris Destoop ◽  
Andrea Minoia ◽  
Oleksandr Ivasenko ◽  
Aya Noguchi ◽  
Kazukuni Tahara ◽  
...  
Keyword(s):  
Self Assembled Monolayers ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Chiral Induction ◽  
Dimensional Network ◽  
Assembled Monolayers ◽  
Self Assembled ◽  
The Impact ◽  
Atomically Flat ◽  
Origin Of Homochirality

Chiral induction in self-assembled monolayers has garnered considerable attention in the recent past, not only due to its importance in chiral resolution and enantioselective heterogeneous catalysis but also because of its relevance to the origin of homochirality in life. Here, we demonstrate the emergence of homochirality in a supramolecular low-density network formed by achiral molecules at the interface of a chiral solvent and an atomically-flat achiral substrate. We focus on the impact of structure and functionality of the adsorbate and the chiral solvent on the chiral induction efficiency in self-assembled physisorbed monolayers, as revealed by scanning tunneling microscopy. Different induction mechanisms are proposed and evaluated, with the assistance of advanced molecular modeling simulations.

scholarly journals Entropic Analysis of Mirror Symmetry Breaking in Chiral Hypercycles

Life ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 28 ◽  
Author(s):  
David Hochberg ◽  
Josep Ribó
Keyword(s):  
Symmetry Breaking ◽  
Entropy Production ◽  
Mirror Symmetry ◽  
Flow Reactor ◽  
Evolutionary Selection ◽  
Replicator System ◽  
Stoichiometric Network Analysis ◽  
Underlying Mechanisms ◽  
The Individual ◽  
Origin Of Homochirality

Replicators are fundamental to the origin of life and evolvability. Biology exhibits homochirality: only one of two enantiomers is used in proteins and nucleic acids. Thermodynamic studies of chemical replicators able to lead to homochirality shed valuable light on the origin of homochirality and life in conformity with the underlying mechanisms and constraints. In line with this framework, enantioselective hypercyclic replicators may lead to spontaneous mirror symmetry breaking (SMSB) without the need for additional heterochiral inhibition reactions, which can be an obstacle for the emergence of evolutionary selection properties. We analyze the entropy production of a two-replicator system subject to homochiral cross-catalysis which can undergo SMSB in an open-flow reactor. The entropy exchange with the environment is provided by the input and output matter flows, and is essential for balancing the entropy production at the non-equilibrium stationary states. The partial entropy contributions, associated with the individual elementary flux modes, as defined by stoichiometric network analysis (SNA), describe how the system’s internal currents evolve, maintaining the balance between entropy production and exchange, while minimizing the entropy production after the symmetry breaking transition. We validate the General Evolution Criterion, stating that the change in the chemical affinities proceeds in a way as to lower the value of the entropy production.

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