Mossbauer and electron paramagnetic resonance studies of chloroperoxidase following mechanism-based inactivation with allylbenzene

摘要

We have used Mossbauer and electron para- magnetic resonance (EPR) spectroscopy to study a heme-N- alkylated derivative of chloroperoxidase (CPO) prepared by mechanism-based inactivation with allylbenzene and hydrogen peroxide. The freshly prepared inactivated enzyme ("green CPO") displayed a nearly pure low-spin ferric EPR signal with g = 1.94, 2.15, 2.31. The Mossbauer spectrum of the same species recorded at 4.2 K showed magnetic hyperfine splittings, which could be simulated in terms of a spin Hamiltonian with a complete set of hyperfine parameters in the slow spin fluctuation limit.