Active sites of two orthologous cytochromes P450 2E1: differences revealed by spectroscopic methods.
Cytochromes P450 2E1 of human and minipig origin were examined by absorption spectroscopy under high hydrostatic pressure and by resonance Raman spectroscopy. Human enzyme tends to denature to the P420 form more easily than the minipig form; moreover, the apparent compressibility of the heme active site (as judged from a redshift of the absorption maximum with pressure) is greater than that of the minipig counterpart. Relative compactness of the minipig enzyme is also seen in the Raman spectra, where the presence of planar heme conformation was inferred from band positions characteristic of the low-spin heme with high degree of symmetry. In this respect, the CYP2E1 seems to be another example of P450 conformational heterogeneity as shown, e.g., by Davydov et al. for CYP3A4 [Biochem. Biophys. Res. Commun. 312 (2003) 121-130]. The results indicate that the flexibility of the CYP active site is likely one of its basic structural characteristics.
Anzenbacherova
Eva
E
Institute of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacky University, CZ-775 15 Olomouc, Czech Republic.
Hudecek
Jiri
J
Murgida
Daniel
D
Hildebrandt
Peter
P
Marchal
Stéphane
S
Lange
Reinhard
R
Anzenbacher
Pavel
P
D000818:Animals; D001665:Binding Sites; D019392:Cytochrome P-450 CYP2E1 / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D013053:Spectrophotometry / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013552:Swine
D019392:Cytochrome P-450 CYP2E1