I am really fascinated by life's origins and the homochirality problem is one of the greatest mysteries in the origins of life research. First noticed by Louis Pasteur more than a century ago, biological homochirality is a fascinating phenomenon linking the physical aspects of nature to life as we know it. Being a physicist and working on a very interdisciplinary problem, I am hoping to see that a fundamental interaction in physics can give rise to a ubiquitous feature of life on Earth.
Life needs essential biomolecules like amino acids and sugars, which exist as mirror symmetrical pairs, just like your hands. Yet, biological systems selectively use only one handedness of these pairs: sugars in biology are right-handed, and amino acids in biology are left-handed. Hence, the life is said to be homochiral. However, what is the physical reason behind this feature of life on Earth?
Despite the importance of homochirality for life and its emergence, its origin remains elusive. I investigate this longstanding mystery.
Despite the importance of homochirality for life and its emergence, its origin remains elusive. I investigate this longstanding mystery.
If life displays homochirality, then the prebiotic chemistry leading to the origin of life should lead to the emergence of this property. In order to achieve homochirality in a chemical network, it is necessary to have a mechanism that can break the chiral symmetry, inducing an imbalance between the two enantiomers. Furthermore, this induced imbalance must be amplified to reach a homochiral state in a persistent basis. Finally, the chiral information must be effectively spread across the prebiotic network such that network-wide homochirality can be realized.
Due to the chiral-induced spin selectivity (CISS) effect, which established a strong coupling between electron spin and molecular chirality, magnetic surfaces with net magnetization can function as chiral agents and be templates for the enantioselective crystallization of chiral molecules. Hence, through the spin-chirality coupling established by the CISS effect, the chiral symmetry of life can be broken on magnetic surfaces abundant on early Earth!
Due to the chiral-induced spin selectivity (CISS) effect, which established a strong coupling between electron spin and molecular chirality, magnetic surfaces with net magnetization can function as chiral agents and be templates for the enantioselective crystallization of chiral molecules. Hence, through the spin-chirality coupling established by the CISS effect, the chiral symmetry of life can be broken on magnetic surfaces abundant on early Earth!
In our recent studies, we have demonstrated that, due to the CISS effect magnetic surfaces can act as templates for the enantioselective crystallization of a ribonucleic acid (RNA) precursor. Moreover, we have shown that, conglomerate crystallization can accompany the chiral symmetry breaking by the magnetic surface as a simultaneous and well-matched amplification mechanism. By combining these two necessary features to reach homochirality, we obtained enantiopure crystals of ribose-aminooxazoline (RAO) on magnetite surfaces, from a fully racemic solution of RAO.
Last but not least, the emergence of homochirality at the stage of RAO allows for the propagation of homochirality through D-RNA to L-peptides and therefore to the entire prebiotic network. With these features, we established RAO as an important prebiotic compound which can play a central role in the origin of homochirality.
Homochirality problem is fascinating, and I aim to contribute to its solution through my research, which I have attempted to summarize here. I am working with my collaborators to develop more refined scenarios that will help us further elucidate and improve upon our results. Our recent breakthroughs are just the beginning of many more discoveries to come!
Selected publications:
- Ozturk, S. Furkan “A New Spin on the Origin of Biological Homochirality” Doctoral dissertation, Harvard University Graduate School of Arts and Sciences (2024).
- 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).
- Ozturk, S. Furkan, et al. “Chirality-induced avalanche magnetization of magnetite by an RNA precursor” Nature Communications (2023).
- 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?” The Journal of Chemical Physics (2023).
