Harvard University, Department of Physics
Abstract: Life requires essential biomolecules such as amino acids and sugars, which exist in mirror symmetrical pairs. However, biological systems are homochiral; they selectively use only one form of these pairs: right-handed sugars and left-handed amino acids. The origin of this asymmetry remains an open problem, and it is this long-standing mystery that we address in this work. The chiral-induced spin selectivity (CISS) effect has established a strong coupling between electron spin and molecular chirality, and this coupling paves the way for breaking the chiral molecular symmetry by spin-selective processes. Magnetic surfaces can act as chiral agents due to the CISS effect, and they can be templates for the enantioselective crystallization of chiral molecules. In this work, we studied the spin-selective crystallization of racemic ribo-aminooxazoline (RAO), an RNA precursor, on magnetite surfaces, achieving homochirality in two crystallization steps. Moreover, we have shown the chirality-induced magnetization of magnetite by RAO molecules, proving the reciprocal nature of the effect. Finally, we suggest a pathway by which the attained homochirality at RAO can effectively propagate from RNA to peptides and then to metabolites—paving the way for achieving a fully homochiral network. Our results demonstrate a prebiotically plausible way of achieving systems-level homochirality from completely racemic starting materials.
Selected publications:
1. Ozturk, S. Furkan, and Sasselov, Dimitar D. “On the origins of life’s homochirality: Inducing enantiomeric excess with spin-polarized electrons” PNAS (2022)
2. Ozturk, S. Furkan, Liu, Ziwei, Sutherland, John D., Sasselov, Dimitar D. “Origin of biological homochirality by crystallization of an RNA precursor on a magnetic surface” Science Advances (2023)
3. Ozturk, S. Furkan, et al. “Chirality-induced avalanche magnetization of magnetite by an RNA precursor” Nature Communications (2023)
4. Ozturk, S. Furkan, Sasselov, Dimitar D. and Sutherland, John D. “The central dogma of biological homochirality: How does chiral information propagate in a prebiotic network?” JCP (2023)
Research highlight:
· Service, Robert. (2023). ‘Breakthrough’ could explain why life molecules are left- or right-handed. Science, 380-6650.
· Saplakoglu, Yasemin. (2023). Magnetism May Have Given Life Its Molecular Asymmetry. Quanta Magazine
· Greed, S. (2022). The dawn of asymmetry. Nature Reviews Chemistry, 1-
· Bloom, B. P., Waldeck, A. R., & Waldeck, D. H. (2022). Homochirality and chiral-induced spin selectivity: A new spin on the origin of life. PNAS, 119(34), e2210505119.