Deciphering the biotransformation mechanism of dialkylresorcinols by CYP4F11.

Cytochrome P450 enzymes (CYPs) are one of the most important classes of oxidative enzymes in the human body, carrying out metabolism of various exogenous and endogenous substrates. In order to expand the knowledge of these enzymes' specificity and to obtain new natural product derivatives, CYP4F11, a cytochrome P450 monooxygenase, was used in the biotransformation of dialkylresorcinols 1 and 2, a pair of antibiotic microbial natural products. This investigation resulted in four biotransformation products including two oxidative products: a hydroxylated derivative (3) and a carboxylic acid derivative (4).

Exploring the Chemical Space of Proluciferins as Probe Substrates for Human Cytochrome P450 Enzymes.

We report the synthesis of 21 new proluciferin compounds that bear a small aliphatic ether group connected to the 6' hydroxy function of firefly luciferin and either contain an acid or methyl ester function at the dihydrothiazole ring. Each of these compounds was found to be a substrate for some members of the human CYP1 and CYP3 families; a total of 92 new enzyme-substrate pairs were identified. In a screen of the whole human P450 complement (CYPome) with three selected proluciferin acid substrates, another 13 enzyme-substrate pairs were detected, which involve enzymes belonging to the CYP2, CYP4, CYP7, CYP21, and CYP27 families.

Conversion of five proluciferin esters by human cytochrome P450 enzymes.

Background: Probe substrates are an important tool for activity monitoring of human drug metabolizing enzymes such as cytochromes P450 (CYPs).

Brief Methods: In the present study we have tested human CYPs for metabolization of five proluciferin ester substrates which had previously only been known to be hydroxylated by CYP26A1.

Major Results: It was found that these substrates were converted by another 21 human CYPs, which belong to the CYP families 1 to 4, 7, and 26.

New luciferin-based probe substrates for human CYP26A1.

Activity of human CYP26A1 towards six proluciferin probe substrates and their ester derivatives was monitored. These included three monofluorobenzyl ether isomers and three five-membered heterocycles. Overall, luciferin substrates with a free acid group gave higher activities than the ester compounds.

Screening of the whole human cytochrome P450 complement (CYPome) with enzyme bag cocktails.

We have previously introduced the use of permeabilized fission yeast cells (enzyme bags) that recombinantly express full-length CYPs for drug metabolism studies. Such enzyme bags are cells with pores that function as enzymes . They can easily be prepared without a need for ultracentrifugation and may be used in similar protocols as microsomes.

Identification of new probe substrates for human CYP20A1.

CYP20A1 is a well-conserved member of the human cytochrome P450 enzyme family for which no endogenous or xenobiotic substrate is known. We have recently shown that this enzyme has moderate activity towards two proluciferin probe substrates. In order to facilitate the search for physiological substrates we have tested nine additional proluciferins in this study and identified three such probe substrates that give much higher product yields.