Quantum tunneling events occurring through biochemical bonds are capable of generating quantum correlations between bonded systems, which in turn makes the conventional second law of thermodynamics approach insufficient to investigate these systems. This means that the utilization of these correlations in their biological functions could give an evolutionary advantage to biomolecules to an extent beyond the predictions of molecular biology that are generally based on the second law in its standard form. To explore this possibility, we first compare the tunneling assisted quantum entanglement shared in the ground states of covalent and hydrogen bonds. Only the latter appears to be useful from a quantum information point of view. Also, significant amounts of quantum entanglement can be found in the thermal state of hydrogen bond. Then, we focus on an illustrative example of ligand binding in which a receptor protein or an enzyme is restricted to recognize its ligands using the same set of proton-acceptors and donors residing on its binding site. In particular, we show that such a biomolecule can discriminate between [Formula: see text] agonist ligands if it uses the entanglement shared in [Formula: see text] intermolecular hydrogen bonds as a resource in molecular recognition. Finally, we consider the molecular recognition events encountered in both the contemporary genetic machinery and its hypothetical primordial ancestor in pre-DNA world, and discuss whether there may have been a place for the utilization of quantum entanglement in the evolutionary history of this system.
Quantum tunneling events occurring through biochemical bonds are capable of generating quantum correlations between bonded systems, which in turn makes the conventional second law of thermodynamics approach insufficient to investigate these systems. This means that the utilization of these correlations in their biological functions could give an evolutionary advantage to biomolecules to an extent beyond the predictions of molecular biology that are generally based on the second law in its standard form. To explore this possibility, we first compare the tunneling assisted quantum entanglement shared in the ground states of covalent and hydrogen bonds. Only the latter appears to be useful from a quantum information point of view. Also, significant amounts of quantum entanglement can be found in the thermal state of hydrogen bond. Then, we focus on an illustrative example of ligand binding in which a receptor protein or an enzyme is restricted to recognize its ligands using the same set of proton-acceptors and donors residing on its binding site. In particular, we show that such a biomolecule can discriminate between [Formula: see text] agonist ligands if it uses the entanglement shared in [Formula: see text] intermolecular hydrogen bonds as a resource in molecular recognition. Finally, we consider the molecular recognition events encountered in both the contemporary genetic machinery and its hypothetical primordial ancestor in pre-DNA world, and discuss whether there may have been a place for the utilization of quantum entanglement in the evolutionary history of this system.
Abstract The role of proton tunnelling in biological catalysis is investigated here within the frameworks of quantum information theory and thermodynamics. We consider the quantum correlations generated through two hydrogen bonds between a substrate and a prototypical enzyme that first catalyses the tautomerization of the substrate to move on to a subsequent catalysis, and discuss how the enzyme can derive its catalytic potency from these correlations. In particular, we show that classical changes induced in the binding site of the enzyme spreads the quantum correlations among all of the four hydrogen-bonded atoms thanks to the directionality of hydrogen bonds. If the enzyme rapidly returns to its initial state after the binding stage, the substrate ends in a new transition state corresponding to a quantum superposition. Open quantum system dynamics can then naturally drive the reaction in the forward direction from the major tautomeric form to the minor tautomeric form without needing any additional catalytic activity. We find that in this scenario the enzyme lowers the activation energy so much that there is no energy barrier left in the tautomerization, even if the quantum correlations quickly decay.
• A study published in the international journal Communications Physics demonstrated the phenomenon of proton tunneling inside DNA utilizing an open quantum systems approach. • The research confirmed that protons within DNA hydrogen bonds pass through binding barriers via quantum tunnelling, going well beyond simple thermal fluctuations, and that this plays a dominant role in the conversion of base pairs into rare tautomers. • This is a groundbreaking result proving that the fundamental genetic mutation process of life is driven by microscopic quantum tunneling probabilities, revealing that tautomeric states can induce natural point mutations. [Quantum Biology Society] The DNA double helix, which contains all the genetic information of living organisms, is stably maintained by hydrogen bonds between base pairs. However, even in this robust structure, unexplained point mutations occasionally occur, becoming the seeds of evolution and disease. Recently, a study demonstrating that quantum tunnelling—a bizarre physical law of the subatomic world—is deeply involved behind this fundamental biological phenomenon was published, surprising both the biology and physics communities. The paper detailing this groundbreaking discovery, titled "An open quantum systems approach to proton tunnelling in DNA," was made freely available in Communications Physics, a sister journal to the world-renowned Nature. A research team consisting of Louie Slocombe, Marco Sacchi, and Jim Al-Khalili from the University of Surrey in the UK led this interdisciplinary study. ■ The Power of Quantum Tunneling Beyond Classical Chemistry From the perspective of general classical biochemistry, it has been assumed that for protons forming DNA hydrogen bonds to change positions, sufficient thermal fluctuation is required to overcome the binding barrier. However, the researchers discovered a surprising fact through an open quantum systems model that precisely reflects the effects of decoherence and dissipation within the cellular environment. Protons instantly change their binding positions through quantum tunneling, passing through the barrier despite a lack of energy, and the contribution of quantum tunneling to the chemical reaction rate is several orders of magnitude larger than classical over-the-barrier hopping. ■ The Beginning of Mutation: Tautomeric Conversion According to the analysis, this quantum tunneling plays a dominant role in the conversion of Guanine-Cytosine (G-C) base pairs from their canonical form into highly rare and unstable tautomeric forms. The problem arises when the DNA strands are separated by the helicase enzyme and replication occurs in this state. The research team confirmed that at biological temperatures (around 300K), the thermal equilibrium occupation probability of the tautomer reaches an astoundingly high value of 1.73 × 10⁻⁴. This is significantly higher than the previously known natural spontaneous mutation rate (about 10⁻⁸), strongly suggesting that tautomerisation via quantum tunneling is a substantial and crucial cause of point mutations. ■ Presenting a New Paradigm in Life Sciences This study is a monumental achievement proving that genetic stability and the mutation process—the most fundamental and secretive domain of life—are not accidental chemical mistakes but are directly driven by the probability of quantum tunneling, a physical law of the microscopic world. This is a powerful demonstration that overturns the conventional view of interpreting biological phenomena solely through macroscopic molecular structures and chemical bonds, showing that quantum mechanics can be the key to fully explaining genetic mutation models.
Abstract The second quantum revolution is all about exploiting the quantum nature of atoms and molecules to execute quantum information processing tasks. To boost this growing endeavor and by anticipating the key role of quantum chemistry therein, our work establishes a framework for systematically exploring, quantifying and dissecting correlation effects in molecules. By utilizing the geometric picture of quantum states we compare—on a unified basis and in an operationally meaningful way—total, quantum and classical correlation and entanglement in molecular ground states. To unlock and maximize the quantum informational resourcefulness of molecules an orbital optimization scheme is developed, leading to a paradigm-shifting insight: a single covalent bond equates to the entanglement 2 ln ( 2 ) . This novel and more versatile perspective on electronic structure suggests a generalization of valence bond theory, overcoming deficiencies of modern chemical bonding theories.
Introduction In this chapter, we will focus on the phenomenon of quantum entanglement . Entanglement is a special property that some states of two or more quantum particles may possess. When particles are in an entangled state they are correlated. But entanglement is far more than mere correlation . Entanglement is a type of correlation that macroscopic objects cannot have, even in principle; it is what we call a ‘non-local’ correlation. Entanglement, and the non-locality that derives from it, is by now considered to be, arguably, the most important aspect of quantum mechanics. Philosophically it leads to many puzzles and to a complete change in our view of nature. At the same time, the practical implications of this type of correlation are very significant. In particular, they can lead to the dramatically enhanced information processing capabilities that quantum systems possess. The whole field of quantum information processing (Steane, 1998; Bennett and DiVincenzo, 2000; Zoller et al. , 2005) has entanglement at its core. Given the above, it is natural to ask whether biological systems make use and take advantage of the enhanced possibilities that entanglement offers. It seems natural to expect this, especially at biological molecular level, where the laws of quantum mechanics apply. Entanglement between two isolated particles is easy to obtain: almost every time two particles interact they get entangled. But entanglement is very fragile. When two entangled quantum systems interact with a third, they easily become entangled in a tri-partite way; however, any entanglement between any two of them is reduced or disappears altogether.
DNA contains all of the genetic information necessary to grow and sustain life and it is designed in such a way as to be remarkably stable despite it’s complexities. This paper discusses the inherent quantum mechanical nature of the hydrogen bonds in DNA nucleotides, specically the occurrence of proton tunneling within the hydrogen bond and the implications this has on the integrity of DNA replication as a whole. This paper also touches upon the eect radiation has on the frequency of proton tunneling in hydrogen bonds and the deleterious results it has on DNA replication integrity.
Molecular biology and biochemistry interpret microscopic processes in the living world in terms of molecular structures and their interactions, which are quantum mechanical by their very nature. Whereas the theoretical foundations of these interactions are well established, the computational solution of the relevant quantum mechanical equations is very hard. However, much of molecular function in biology can be understood in terms of classical mechanics, where the interactions of electrons and nuclei have been mapped onto effective classical surrogate potentials that model the interaction of atoms or even larger entities. The simple mathematical structure of these potentials offers huge computational advantages; however, this comes at the cost that all quantum correlations and the rigorous many-particle nature of the interactions are omitted. In this work, we discuss how quantum computation may advance the practical usefulness of the quantum foundations of molecular biology by offering computational advantages for simulations of biomolecules. We not only discuss typical quantum mechanical problems of the electronic structure of biomolecules in this context, but also consider the dominating classical problems (such as protein folding and drug design) as well as data-driven approaches of bioinformatics and the degree to which they might become amenable to quantum simulation and quantum computation.