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CATALYTIC ACTIVITY OF CYTOCHROME P‐450 USING NADP+ REDUCED BY SILICA HYDRIDE
Author(s) -
Hernandez Martha cecilia rosales,
Pérez Sandra selene Ortiz,
Aceves Jose manuel,
Basurto Jose Correa,
Rosales Daniel Ramírez,
Ulloa Rafael Zamorano,
Ferrara Jose Trujillo
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a670
Subject(s) - hydride , chemistry , catalysis , cofactor , biotransformation , cytochrome p450 , active site , enzyme , silica gel , stereochemistry , photochemistry , medicinal chemistry , inorganic chemistry , organic chemistry , hydrogen
Cytochrome P‐450 (P450)enzymes play an important role during the drug metabolism due to it catalyzes a great amoung of reactions. However, their use for in vitro assays has several limitations, the main one is the use of the cofactor (NADPH). In this work the catalytic activity of P450 using NADP+ reduced with silica hydride was evaluated. The results obtained showed that the reduction of NADP+ with silica hydride was concentration and time‐dependent. In addition, P450 mantained its activity when NADP+ and silica hydride were added during the reaction, however its activity was less than when NADPH was employed. It is due to the fact that silica hydride is able to reduce not only to NADP+ but also to iron atom from P450, avoiding or diminishing the aniline affinity by the active site. The reduction of the iron atom with silica hydride was corroborated by electronic paramagnetic resonance (EPR). On the other hand, when NADP+ was reduced with silica hydride before being added to the reaction, the P450 activity was better than when NADPH was used. Therefore, it is worthnoting that the use of NADP+ reduced with silica hydride before to be added to the reaction could be a good system for studying biotransformation reactions.