Physical limits to magnetogenetics

TL;DR

This paper critically examines the physical plausibility of recent claims in magnetogenetics, arguing that reported magnetic effects in biological systems conflict with fundamental physics and are unlikely to be feasible with current understanding.

Contribution

It provides a physics-based critique of magnetogenetics claims, highlighting fundamental limitations and discrepancies with established physical laws.

Findings

Reported magnetic effects are inconsistent with basic physics.

Paramagnetic properties of proteins limit their use in magnetogenetics.

Claims of magnetic control in biology likely have alternative explanations.

Abstract

This is an analysis of how magnetic fields affect biological molecules and cells. It was prompted by a series of prominent reports regarding magnetism in biological systems. The first claims to have identified a protein complex that acts like a compass needle to guide magnetic orientation in animals (Qin et al., 2016). Two other articles report magnetic control of membrane conductance by attaching ferritin to an ion channel protein and then tugging the ferritin or heating it with a magnetic field (Stanley et al., 2015; Wheeler et al., 2016). Here I argue that these claims conflict with basic laws of physics. The discrepancies are large: from 5 to 10 log units. If the reported phenomena do in fact occur, they must have causes entirely different from the ones proposed by the authors. The paramagnetic nature of protein complexes is found to seriously limit their utility for engineering magnetically sensitive cells.