Experimental evidence for long-distance electrodynamic intermolecular forces

" Both Classical and Quantum Electrodynamics predict the existence of dipole-dipole long-range electrodynamic intermolecular forces, however these have never been hitherto experimentally observed. The discovery of completely new and unanticipated forces acting between biomolecules could have considerable impact on our understanding of the dynamics and functioning of the molecular machines at work in living organisms. Here, using two independent approaches, we demonstrate experimentally for the first time the activation of resonant electrodynamic intermolecular forces. We characterize clustering transitions induced by these forces by fluorescence correlation spectroscopy when out-of-equilibrium conditions induce collective molecular oscillation observed by Terahertz (THz) spectroscopy. This is an unprecedented experimental proof of principle of a physical phenomenon that, having been observed for bio-macromolecules and with a long-range of action (up to 1000 Å), could be of importance for biology. Therefore, in addition to thermal fluctuations that drive molecular motion randomly, these resonant (and thus selective) electrodynamic forces may contribute to molecular encounters in the crowded cellular space. We anticipate our findings will provide a basis for future systematic deepening of physical aspects of the reported phenomena and for future systematic assessment of the relevance of electrodynamic forces in shaping the dynamics of biomolecular encounters and recognition in biology."

" ... free diffusion is considerably slowed down in a highly crowded environment [3] as in the case of the cell interior. Moreover, when diffusion measurements are performed in complex molecular organizations such as those of living cells, most of the biomolecules show anomalous rather than Brownian diffusion [4, 5]. Furthermore, structuring of the cytosol into phase-separated domains [6, 7], substrate channeling of the metabolons [8], or long-distance interactions in DNA searching [9] and organization [10] have recently come to the forefront to question the discrepancy between the observed reaction rates in cells with the predictions of a strict random diffusion model [6, 11]. Within this framework, dipole-dipole electrodynamic interactions are predicted to promote molecular attraction by being selective through resonance and to act over long distances [12]."

" In the work presented here, we have experimentally shown, for the first time, that the excitation of out-of-equilibrium collective oscillations is capable of driving molecular association through the activation of electrodynamic intermolecular forces. R-PE provides convincing evidence for these forces using a pair of complementary experimental approaches. Thus, R-PE represents the “Rosetta stone” allowing us to identify attractive intermolecular forces through two completely different physical effects."

" Here, the energy sources necessary to maintain the molecules out-of-equilibrium need to be characterized. Among the potential candidates, there are: adenosine triphosphate (ATP) as a universal biological fuel, ionic currents such as those used to drive ATP synthesis, ionic collisions, photons produced by mitochondria, or external light."