Different structure of the complexes of two cytochrome P-450 isozymes with acetanilide by 1H-NMR relaxation and spectrophotometry.
The functional and spectral characteristics of the interaction of acetanilide with phenobarbital- and methylcholanthrene- induced rat liver microsomes, as well as with corresponding major isozymes (cytochromes P-450b and P-450c) have been compared. The magnitude of the reverse 1st type binding spectra proved to be negatively correlated with the acetanilide oxidation on isozymes under study. The data on paramagnetic relaxation of acetanilide protons in the presence of P-450 have shown the structure of the enzyme-substrate complex to be different for two isozymes, acetanilide molecule being closer to Fe ion in the active site in the case of P-450c, which is active towards acetanilide oxidation. For the P-450c-acetanilide complex the group oxidized (phenyl) is the closest to Fe ion.
Institute of Molecular Pathology & Ecological Biochemistry, Novosibirsk, Russia.
Woldman YaYu
L M
LM
Weiner
V V
VV
Lyakhovich
D000083:Acetanilides / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D007527:Isoenzymes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology; D011487:Protein Conformation; D011522:Protons; D051381:Rats; D017208:Rats, Wistar; D013053:Spectrophotometry
D000083:Acetanilides; D007527:Isoenzymes; D011522:Protons; D003577:Cytochrome P-450 Enzyme System