Speed of protein conformational change?
This paper uses &quot;ultrafast 2D-IR vibrational echo chemical-exchange spectroscopy&quot; to track switching between different protein conformations and finds that they take place on the order of 50 pico-seconds ($ 1 \times 10^{-12} $ seconds). Another paper finds something similar but notes that full equilibriation can take on the order or nanoseconds:

Although the main conformational change of the backbone is completed after only 20 ps, the subsequent equilibration in the new region of conformational space continues for times &gt;16 ns.