ABC Transporters are billion-year-old Maxwell Demons

Abstract

ABC transporters are a broad family of biological machines, found in most prokaryotic and eukaryotic cells, performing the crucial import or export of substrates through both plasma and organellar membranes, and maintaining a steady concentration gradient driven by ATP hydrolysis. Building upon the present biophysical and biochemical characterization of ABC transporters, we propose here a model whose solution reveals that these machines are an exact molecular realization of the Maxwell Demon, a century-old abstract device that uses an energy source to drive systems away from thermodynamic equilibrium. In particular, the Maxwell Demon does not perform any direct mechanical work on the system, but simply selects which spontaneous processes to allow and which ones to forbid based on information that it collects and processes. In the molecular model introduced here, the different information-processing steps that characterize Maxwell Demons (measurement, feedback and resetting) are features that emerge from the biochemical and structural properties of ABC transporters, allowing us to develop an explicit bridge between the molecular level description and the higher-level language of information theory.

Roadmap for optical tweezers

“…By measuring energy and information, optical tweezers combined with other techniques, permit us accurate and better measurements of entropy production and information, in molecular and cellular systems, and beyond. Nanothermodynamics shows the path to measure information in a bit-wise sense in biological processes, where the key steps of autonomous Maxwell demons (measurement, feedback, and information erasure) are naturally encoded [290]. As put forward by François Jacob [291], evolutionary processes are akin to bricolage (do-it-yourself), where nature uses everything that is available to improve what does already exist.…”

Sentient cells as basic units of tissues, organs and organismal physiology

“…Besides the cytoskeleton, the cellular sentience‐generating apparatus is based on the excitable plasma membrane populated by numerous sensors, receptors, channels and diverse transporters, working together as biological versions of Maxwell demons (Boël et al., 2019; Mizraji, 2021; Flatt et al., 2023). Together, these cellular architectural elements constitute the bulwark of cellular senomic awareness.…”

Rules, hypergraphs, and probabilities: the three-level analysis of chemical reaction systems and other stochastic stoichiometric population processes

“…Moreover, for many biologically relevant transductions between redox, phosphate, or proton energy systems, the full transduction occurs through multiple reactions in series, which may exchange buffered species such as protons or water with the solvent. Thus free energy transduced between feasible processes v 1 and v 2 that jointly with v| (ji) make a null flow may exchange chemical work both by transduction through v| (ji) and by direct exchange 10 One can view the molecular "turnstyles" and "escapements" [76,77] that transduce free energy between processes that are not stoichiometrically coupled by chemical necessity as evolved mechanisms to impose high kinetic barriers along sequences of reactions coupled to a succession of overlapping inputs and outputs [78].…”