Description:
<jats:p>The relaxation kinetics of the temperature‐dependent spin equilibrium of cytochrome P450 LM2 has been resolved by means of a laser temperature‐jump device. The Nd laser system in the Q‐switched mode delivers 3 J/25 ns pulses which were Raman shifted to 1.89 μm by use of a high pressure H<jats:sub>2</jats:sub>‐gas cell. The LM2 equilibrium relaxation proceeds in the ns‐range, the rate constants of the on‐ and off‐reactions amount to about 10<jats:sup>6</jats:sup> s<jats:sup>−1</jats:sup> in correspondence with respective processes of other hemoproteins and protein‐free model compounds. Benzphetamine increases the on‐rate constant (low‐spin → high‐spin) about 5 fold, the off‐process is nearly unchanged.</jats:p>