Defining resonance Raman spectral responses to substrate binding by cytochrome P450 from Pseudomonas putida.

Resonance Raman spectra are reported for substrate-free and camphor-bound cytochrome P450cam and its isotopically labeled analogues that have been reconstituted with protoheme derivatives that bear -CD(3) groups at the 1, 3, 5, and 8-positions (d12-protoheme) or deuterated methine carbons (d4-protoheme). In agreement with previous studies of this and similar enzymes, substrate binding induces changes in the high frequency and low frequency spectral regions, with the most dramatic effect in the low frequency region being activation of a new mode near 367 cm(-1). This substrate-activated mode had been previously assigned as a second "propionate bending" mode (Chen et al.