ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Homochirality.pdf (883.56 kB)

Homochirality Is Originated from Handedness of Helices

preprint
submitted on 02.07.2020 and posted on 06.07.2020 by Shubin Liu
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 310-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.

History

Email Address of Submitting Author

shubin@email.unc.edu

Institution

University of North Carolina at Chapel Hill

Country

USA

ORCID For Submitting Author

0000-0001-9331-0427

Declaration of Conflict of Interest

No conflict of interest

Exports