Biochemistry & Organic Chemistry

Solvent Constraints For Biopolymer Folding And Evolution In Extraterrestrial Environments

By Keith Cowing
Status Report
October 14, 2023
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Solvent Constraints For Biopolymer Folding And Evolution In Extraterrestrial Environments
Temperature domains of water and terrestrial biopolymers at atmospheric pressure. Left: temperature domains of stability and metastability for liquid and glassy water (black) and dynamic transition (red) (11–13). Equilibrium transitions are shown as full lines, kinetically controlled transitions as dashed lines. Right: temperature domains and glass transition for folding of terrestrial biopolymers (blue). Circles indicate proteins (15–19, 27), squares indicate RNA (16, 20–22) and triangles indicate DNA (23–26). Above the glass transition temperature (dashed line) a biopolymer can search for its folded form in an efficient manner. Below the biopolymer glass transition temperature a biopolymer is trapped in a rough energy landscape and will not fold in a biology relevant timescale. The theoretical limits for Tsel and Tf calculated from the average glass transition temperature and formula [4] to [6] are shown as continuous lines. Adapted from (11). — astro-ph.EP

We propose that spontaneous folding and molecular evolution of biopolymers are two universal aspects that must concur for life to happen.

These aspects are fundamentally related to the chemical composition of biopolymers and crucially depend on the solvent in which they are embedded. We show that molecular information theory and energy landscape theory allow us to explore the limits that solvents impose on biopolymer existence.

We consider 54 solvents, including water, alcohols, hydrocarbons, halogenated solvents, aromatic solvents, and low molecular weight substances made up of elements abundant in the universe, which may potentially take part in alternative biochemistries. We find that along with water, there are many solvents for which the liquid regime is compatible with biopolymer folding and evolution.

We present a ranking of the solvents in terms of biopolymer compatibility. Many of these solvents have been found in molecular clouds or may be expected to occur in extrasolar planets.

Comments: 25 pages, 6 figures
Subjects: Biomolecules (q-bio.BM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2310.00067 [q-bio.BM] (or arXiv:2310.00067v1 [q-bio.BM] for this version)
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Submission history
From: Diego Ferreiro
[v1] Fri, 29 Sep 2023 18:18:18 UTC (960 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻