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Coauthor of research on temperature-dependent rotation of the ATP synthase F1 sector. The study connected single-molecule motion with subunit interactions during the catalytic dwell, relating enzyme mechanics to energy conversion.^[ref]

Masamitsu Futai coauthored single-molecule studies of F1-ATPase rotation. Measurements of catalytic dwell behaviour probe how interactions among subunits influence the chemical-mechanical cycle.

Changing temperature alters transition rates and can expose different rate-limiting processes. Such measurements link kinetic observations with the architecture of ATP synthase.^[ref]

A biochemist.^[ref]

Mayumi Nakanishi-Matsui coauthored single-molecule measurements of F1-ATPase rotation and its temperature dependence. The work connects gamma-beta subunit interactions with the catalytic dwell.

A motor's average rotation rate can conceal distinct pauses and moving intervals. Resolving individual steps supplies mechanistic information that an average ATP-hydrolysis rate alone cannot provide.^[ref]

A biochemist.^[ref]

Mizuki Sekiya coauthored measurements of the temperature dependence of single-molecule F1 rotation. The study examines how interactions between gamma and beta subunits influence pauses in the catalytic cycle.

A rotation trace separates motion from dwell times. Their different temperature dependences help identify which processes control the timing of a molecular motor.^[ref]

A biochemist.^[ref]

Researcher in ATP-synthase biophysics. Nakamoto coauthored experiments on temperature-dependent single-molecule rotation, connecting interactions between subunits with the catalytic dwell of the motor.^[ref]

In 1997, Hiroyuki Noji and colleagues attached a fluorescent actin filament to the central $\gamma$ shaft of isolated $F_1$. With ATP supplied, the marker made sustained rotations. This exposed rotation directly, but used ATP hydrolysis: there was no membrane $F_0$ motor producing ATP from a proton-motive force in this assay.^[ref]

A subsequent primary experiment made the optical readout much faster. Purified Escherichia coli $F_1$ was immobilized on glass in a $30\mu \mathrm{m}$-deep flow cell, with a $60\mathrm{nm}$ gold bead attached to $\gamma$. With $2\mathrm{mM}$ ATP and magnesium supplied, laser illumination and dark-field microscopy recorded bead positions at $4000$ or $8000$ frames per second. The position trajectory resolved turns and intervening dwells. This apparatus follows a shaft-attached marker, rather than imaging the shaft's chemical atoms.^[ref]

Controls addressed perturbation and chemical activity: comparison of $40$–$200\mathrm{nm}$ probes found similar rates for the two smallest sizes, supporting low drag; a separate coupled-enzyme assay followed ATP hydrolysis through NADH absorbance. But the rotational analysis excluded pauses longer than $0.1\mathrm{s}$, so it characterizes continuously active intervals, not total output including long inhibited periods. It neither counts transported protons nor measures simultaneous single-molecule ATP synthesis.^[ref]

The experimental distinction is essential. Sustained directional marker motion tests a rotary mechanism. Demonstrating proton-driven synthesis additionally requires intact $F_0{F}_1$ in a membrane with a controlled proton-motive force and a chemical ATP-production readout; dependence on that driving force and inhibition or respiratory uncoupling controls then test the proposed energy coupling. A rotation movie alone cannot establish the complete material and free energy ledger.