生命は分子間相互作用におけるニュートンの法則の一見違反に基づくのか?(Is life based on a seeming violation of Newton’s law in molecular interactions?)

2024-03-13

2024-03-12 ペンシルベニア州立大学(PennState)

新たな研究では、すべての行動が反作用を持つわけではないことが明らかになりました。ペンシルバニア州立大学とメイン大学の研究チームが行ったこの研究では、分子間相互作用が進化するメカニズムについての洞察を提供する可能性があります。キナーゼとリン酸化酵素という2つの酵素を対象に、1つの酵素を固定すると他の酵素がそれに引き寄せられることが示されましたが、逆の場合は反発されることが明らかになりました。

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触媒間の非相互作用の分子的起源を探る A molecular origin of non-reciprocal interactions between interacting active catalysts

Niladri Sekhar Manda,Ayusman Sen,R. Dean Astumian
Chem Published:December 29, 2023
DOI:https://doi.org/10.1016/j.chempr.2023.11.017

Highlights

•Diffusion and kinetic asymmetries can give rise to non-reciprocal interactions

•The force at the submicron scale can be estimated and experimentally measured

•Non-reciprocal interactions lead to large fluctuations in particle motion

Summary

Recent work suggests that nonreciprocal interactions are universally present in living systems and constitute an important part of active matter. These interactions, that are in apparent violation of Newton’s third law, break action/reaction symmetry and have been used to describe phenomena such as traveling waves, predator-prey dynamics, and swarming. Here, we elucidate how thermodynamic disequilibrium gives rise to non-reciprocal interactions in molecular systems where the individual molecules remain in mechanical equilibrium. We use a kinase/phosphatase enzyme pair as an illustrative example and show that non-reciprocal interactions between the two arise due to diffusion and kinetic asymmetries in the presence of self-generated substrate and product gradients. The force that kinase exerts on the phosphatase can be repulsive, whereas the phosphatase can exert an attractive force on the kinase. Notably, this chemotactic force is not introduced ad hoc; rather, the molecular origin of nonreciprocity is set by a combination of diffusion and kinetic asymmetry.