The rotation rate carries the result. A 0.4 mm rotor turning 160,000 times a second [5][6] carries its rim at roughly 201 meters per second: pi times 0.4 mm is a circumference near 1.26 mm, and 1.26 mm per turn at 160,000 turns per second comes out around 0.2 km/s [7]. One rotation takes 6.25 microseconds [8]. That period is the clock the physics has to beat.
Magic angle spinning holds the sample at 54.74 degrees to the field and rotates it, which averages out the orientation-dependent forces that smear solid-state spectra [5]. In a protein where every position that can hold a proton still holds one, the dominant broadening is proton-proton dipolar coupling, and Kawamura's group says it is strong enough to make detailed structural information hard to get without deuteration [9]. The conventional fix attacks the same term from the other side, replacing hydrogen with deuterium so there are fewer proton pairs left to couple. That costs money. It can also change the protein's structure, and it brings signal degradation of its own [10]. Spinning faster attacks the coupling without touching the chemistry.
What the team reports is substantially narrower proton linewidths and clearly detected signals from the protonated SzR1 in a hydrated lipid bilayer, from a sub-milligram sample [11][6]. That is a spectroscopy result. The phys.org account describes the group as having developed a method to determine the high-resolution structure of SzR1 [16], while the paper's own title claims something narrower, that ultrafast 160 kHz MAS enables high-resolution proton-detected solid-state NMR of a fully protonated seven-transmembrane protein [2]. One sentence describes resolving signals; the other describes placing atoms, and those are not the same claim. NMR is the technique that ordinarily yields high-resolution structural information [14], so the route is credible; the coordinates are not in this work.
SzR1 is a seven-transmembrane proton pump [3]. The source uses 7TM and G-protein coupled receptor as interchangeable labels, and describes GPCRs as binding extracellular molecules and activating responses inside the cell [4]. Moving protons across a membrane and holding a ligand in an extracellular pocket are not the same measurement problem, and the ligand-bound receptor is not what went into the rotor.
Bruker Biospin and Bruker Japan are two of the four collaborating groups [1], and that is worth noting because the result is defined by a piece of hardware: a 0.4 mm rotor at 160 kHz [6]. The next step Kawamura names stays on the instrument side, pairing ultrafast spinning with magnets above 1 GHz [15].
