scholarly journals Extraterrestrial Chirality

2004 ◽  
Vol 213 ◽  
pp. 139-144 ◽  
Author(s):  
Jeremy Bailey

The homochirality of biological molecules — the almost exclusive use of L-amino acids and D-sugars — is a fundamental property of life, but its origin poses a problem. Recent work has shown an excess of the L enantiomer in amino acids in the Murchison and Murray meteorites, supporting the model, first proposed by Rubenstein et al. (1983) of an extraterrestrial origin for homochirality. This paper discusses the evidence for extraterrestrial chiral asymmetry, the processes which could have led to such asymmetry, and the possible relevance for the origin of biological homochirality on Earth.

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Ashraf Marzouk El Tantawi

RORs isoforms are so active biological molecules in lipid metabolism and in fat biosynthesis, that strongly dependent on and regulated by OPA1 mitochondrial genes and its active mitochondrial enzymes where each of mitochondrial enzyme (phospholipase, synthase, and synthetase) is responsible for its own ROR isoform {phospholipase responsible for ROR-alpha synthesis, synthase responsible for ROR[1]beta synthesis, and synthetase responsible for ROR-gamma synthesis} for acting and functioning the long fatty acids molecules “which produced from the effects of ATPase and COX enzyme on lipid molecules which accompanied and associated with absorbed nutrient molecules (pro-lipo-nutrient -mTOR molecules) “, and then will follow its own pathway in fatty and amino acids biosynthesis, in active anti[1]inflammations biosynthesis, and then will follow its own functions in original cells proliferations.


2020 ◽  
Author(s):  
Durgesh Kumar ◽  
Kamlesh Kumari ◽  
PRASHANT SINGH

Boronic acids are widely used in various applications in view of their ability to recognize and bind at specific sites of the biological molecules to mimic several processes. Therefore, this has attracted the researchers, academician and medical expertise to explore them. In the present work, the authors have designed a theoretical approach to study the interaction of boronic acid with insulin using computational tools. A library of boronic acids (114 compounds) are designed, optimized and interacted with insulin using computational tools i.e. iGEMDOCK. Further, their different biological activities and toxicity are determined. Results indicates the promising potential of the boronic acids on interaction with the insulin. Amongst, 114 molecules of boronic acids, 3-Benzyloxyphenylboronic acid (71) showed the best interaction with amino-acids of insulin and significant interaction was shown with the Glu21 and His5 residues. Further, these results were compared with the stabilizing agents and found to be more potent.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Brooke Thompson ◽  
Kayla Burt ◽  
Andrew Lee ◽  
Kyle Lingard ◽  
Sarah E. Maurer

AbstractWater has many roles in the context of life on Earth, however throughout the universe, other liquids may be able to support the emergence of life. We looked at the ability of amino acids, peptides, a depsipeptide, and proteins to partition into a non-polar decanol phase, with and without the addition of a phase transfer agent. Partitioning evaluated using UV detection, or with HPLC coupled to either charged aerosol detection or ESI-MS. For amino acids and short peptides, phase transfer agents were used to move the biomolecules to the decanol phase, and this transfer was pH dependent. For larger molecules, phase transfer agents did not seem to affect the transfer. Both the depsipetide, valinomycin, and the protein Taq DNA polymerase had solubility in the decanol phase. Additionally, valinomycin appeared to retain its biological ability to bind to potassium ions. These results show that most terrestrial biological molecules are not compatible with non-polar solvents, but it is possible to find and perhaps evolve polymers that are functional in such phases.


Nature ◽  
1972 ◽  
Vol 236 (5341) ◽  
pp. 66-67 ◽  
Author(s):  
JAMES G. LAWLESS ◽  
KEITH A. KVENVOLDEN ◽  
ETTA PETERSON ◽  
CYRIL PONNAMPERUMA ◽  
EUGENE JAROSEWICH

2007 ◽  
Vol 35 (3) ◽  
pp. 502-507 ◽  
Author(s):  
J.A.R. Worrall ◽  
M. Górna ◽  
X.Y. Pei ◽  
D.R. Spring ◽  
R.L. Nicholson ◽  
...  

The principles of self-assembly are described for naturally occurring macromolecules and for complex assemblies formed from simple synthetic constituents. Many biological molecules owe their function and specificity to their three-dimensional folds, and, in many cases, these folds are specified entirely by the sequence of the constituent amino acids or nucleic acids, and without the requirement for additional machinery to guide the formation of the structure. Thus sequence may often be sufficient to guide the assembly process, starting from denatured components having little or no folds, to the completion state with the stable, equilibrium fold that encompasses functional activity. Self-assembly of homopolymeric structures does not necessarily preserve symmetry, and some polymeric assemblies are organized so that their chemically identical subunits pack stably in geometrically non-equivalent ways. Self-assembly can also involve scaffolds that lack structure, as seen in the multi-enzyme assembly, the degradosome. The stable self-assembly of lipids into dynamic membraneous sheets is also described, and an example is shown in which a synthetic detergent can assemble into membrane layers.


1993 ◽  
Vol 20 (5) ◽  
pp. 527 ◽  
Author(s):  
HM Nonhebel ◽  
TP Cooney ◽  
R Simpson

The study of indole-3-acetic acid synthesis has undergone something of a revival recently in an attempt to understand the control of IAA levels. Results are, however, contradictory with three separate hypotheses emerging. Our own work supports older evidence for L-tryptophan as the IAA precursor and appears to simplify the metabolism of tryptophan to IAA. Work comparing incorporation of 2H from 2H2O into IAA, tryptophan, tryptamine and indole-3-pyruvate in tomato shoots showed that the indole-3-pyruvate became labelled at a rate compatible with it being the sole intermediate between tryptophan and indole-3-acetaldehyde. Results also showed that tryptamine was not involved in IAA synthesis although it was present. Indole-3-acetaldoxime was not detected in tomato shoots. An aromatic aminotransferase able to catalyse the synthesis of indole-3-pyruvate has been purified from mung beans. This enzyme was separated from aspartate aminotransferase and is fairly specific for aromatic L-amino acids. Other work, however, has implicated D-tryptophan as a more direct precursor than the L-enantiomer. A D-tryptophan aminotransferase has been isolated from dark grown pea seedlings. Finally, other recent work has indicated the existence of an alternative biosynthetic route to IAA which does not involve tryptophan. These results are reviewed in this paper and the apparent contradictions between them discussed.


2010 ◽  
Vol 24 (3-4) ◽  
pp. 183-190
Author(s):  
Elisabeth S. Papazoglou ◽  
Sundar Babu ◽  
David R. Hansberry ◽  
Sakya Mohapatra ◽  
Chirag Patel

Surface Enhanced Raman Spectroscopy (SERS) has demonstrated significant benefit in the identification of biological molecules. In this paper we have examined how to identify and differentiate the 150 kDa protein myeloperoxidase (MPO) from its corresponding antibody (Ab) and their immunocomplex through the use of SERS. The SERS signal of these biological molecules was enabled by 40 nm gold nanoparticles. The SERS spectra for both MPO and the Ab (an IgG molecule) demonstrated results consistent with previous published work on the Raman spectra of MPO and IgG antibodies. The immunocomplex SERS spectra showed peak shifts and intensity variations that could be attributed to conformational changes that occur during immunocomplex formation. Several key spectral areas have been identified which correspond to specific amino acids being shielded from undergoing resonance while new amino acid residues are made visible in the SERS spectrum of the immunocomplex and could be a result of conformational binding. These results indicate that SERS can be used to identify binding events and distinguish an immunocomplex from its individual components.


Author(s):  
V. M. Zhmakin

The nature of carbon, initial components, molecules of homochiral abiogenic synthesis and their preservation from decay and racemization for more than 4.5 billion years in carbonaceous chondrites has not been established. In the oxygen-free atmospheres of the nebula and early Earth, hydrogen and hydrogen-containing gases were oxidized with carbon monoxide and carbon dioxide to form carbon and water, as well as the intermediates of these reactions, formaldehyde and methane acid. Together with ammonia, they were the initial components of organic synthesis. According to the Rebinder rule, carbon adsorbs hydrogen well, including in organic molecules. In this connection, experiments with the assumed conditions of the early Earth were carried out by adsorption on carbon to obtain R-(rectus, Latin) ribose from formaldehyde, and S-(sinister) serine from formaldehyde, methane acid and ammonia. For other S-amino acids, a stereo chemical justification of their formation based on S-serine is given. For carbonaceous chondrites, the results of the above experiments were confirmed by the correlation of an increase in homochiral excess with an increase in the amount of hydrogen in aldonic acids and lactic acid with a coefficient of 0.94 and 0.85 in amino acids. The justification of the homochiral process will reduce the costs of searching for life on planets, for scientific research, for the production of medicines, perfumes, food, and so on. Doubts about the extraterrestrial origin of homochiral enantiomers in carbonaceous chondrites arise most often due to a lack of understanding of the reasons for their appearance. This work will significantly reduce such skepticism.


2003 ◽  
Vol 31 (6) ◽  
pp. 1238-1242 ◽  
Author(s):  
N. Borgese ◽  
S. Brambillasca ◽  
P. Soffientini ◽  
M. Yabal ◽  
M. Makarow

A group of integral membrane proteins, known as C-tail anchored, is defined by the presence of a cytosolic N-terminal domain that is anchored to the phospholipid bilayer by a single segment of hydrophobic amino acids close to the C-terminus. The mode of insertion into membranes of these proteins, many of which play key roles in fundamental intracellular processes, is obligatorily post-translational, is highly specific and may be subject to regulatory processes that modulate the protein's function. Recent work has demonstrated that tail-anchored proteins translocate their C-termini across the endoplasmic reticulum membrane by a mechanism different from that used for Sec61-dependent post-translational signal-peptide-driven translocation. Here we summarize recent results on the insertion of tail-anchored proteins and discuss possible mechanisms that could be involved.


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