Dissipation During the Gating Cycle of the Bacterial Mechanosensitive Ion Channel Approaches the Landauer’s Limit

Abstract

The Landauer’s principle sets a thermodynamic bound of kBT ln 2 on the energetic cost of erasing each bit of information. It holds for any memory device, regardless of its physical implementation. It was recently shown that carefully built artificial devices can saturate this bound. In contrast, biological computation-like processes, e.g., DNA replication, transcription and translation use an order of magnitude more than their Landauer’s minimum. Here we show that saturating the Landauer bound is nevertheless possible with biological devices. This is done using a mechanosensitive channel of small conductance (MscS) from E. coli as a memory bit. MscS is a fast-acting osmolyte release valve adjusting turgor pressure inside the cell. Our patch-clamp experiments and data analysis demonstrate that under a slow switching regime, the heat dissipation in the course of tension-driven gating transitions in MscS closely approaches its Landauer’s limit. We discuss the biological implications of this physical trait.

Erasing a majority-logic bit

“…On the theoretical side, the framework of stochastic thermodynamics [3,4] has enabled the analysis of specific models and led to general predictions concerning the thermodynamics of finite-time bit erasure [5][6][7][8][9][10][11][12][13][14][15]. Meanwhile, Landauer's principle has been verified on a broad class of experimental systems [16][17][18][19][20][21][22][23][24][25][26]. One general prediction is that the extra work needed to erase a bit over a finite amount of time is inversely proportional to the duration of the protocol, where the proportionality constant depends on the level of control that one has over the system [6,8,9,14,15,27,28].…”

Near-Landauer-Bound Quantum Computing Engineering Using Single Spins

“…Profoundly, Landauer's bound (Figure 10) is accepted as one of the fundamental limits in physics and computer science [19]. Since 2012, Landauer's bound has been experimentally verified for various information carriers, including a single silica glass bead [20], a fluorescent particle [21], a singledomain nanomagnet [8], a single atom [22], a giant spin [9], and bacterial ion channels [23], as summarized in Table 2.…”

“…This effect should appear at low temperatures (when the spin is in its ground state), where it provides an energy-efficient path for magnetic relaxation only if the wavefunction of the left well overlaps with that of the right well. [11] on various information carriers (sorted by the size of the information carrier from large to small, except for the bacterial ion channels [23]). Year Details (Information Carrier) Size T (K) Mode 1961…”

Breaking Landauer's bound in a spin-encoded quantum computer

“…In March 2020, Saira et al measured Landauer's bound at 500 mK [11]. In June 2020, Çetiner et al measured Landauer's bound in ion channels, which are smaller than the florescence molecules [6] but larger than the spins [12].…”