Microtiter plate assays for inhibition of human, drug-metabolizing cytochromes P450.
AuthorsCrespi CL, Miller VP, Penman BW
JournalAnal Biochem
PubMed ID9177742
The photon counting histogram in fluorescence fluctuation spectroscopy.
AuthorsChen Y, Müller JD, So PT, Gratton E
JournalBiophys J
PubMed ID10388780
'Fluorescence correlation spectroscopy (FCS) is generally used to obtain information about the number of fluorescent particles in a small volume and the diffusion coefficient from the autocorrelation function of the fluorescence signal. Here we demonstrate that photon counting histogram (PCH) analysis constitutes a novel tool for extracting quantities from fluorescence ... More
A continuous fluorometric assay for cytochrome P-450-dependent mixed function oxidases using 3-cyano-7-ethoxycoumarin.
AuthorsWhite IN
JournalAnal Biochem
PubMed ID3189781
'A direct fluorometric procedure for the continuous determination of cytochrome P-450-dependent mixed function oxidases, using 3-cyano-7-ethoxycoumarin substrate, is described. The reaction product, 3-cyano-7-hydroxycoumarin, is fluorescent at neutral pH values (excitation and emission wavelength maxima: 408 and 450 nm, respectively). Using hepatic microsomal preparations from control rats, the enzyme(s) had an ... More
Probing ligand protein binding equilibria with fluorescence fluctuation spectroscopy.
AuthorsChen Y, Müller JD, Tetin SY, Tyner JD, Gratton E
JournalBiophys J
PubMed ID10920037
'We examine the binding of fluorescent ligands to proteins by analyzing the fluctuation amplitude g(0) of fluorescence fluctuation experiments. The normalized variance g(0) depends on the molecular brightness and the concentration of each species in the sample. Thus a single g(0) measurement is not sufficient to resolve individual species. Titration ... More
Fluorescence of substituted 7-hydroxycoumarins.
AuthorsSherman WR, Robins E
JournalAnal Chem
PubMed ID5641323
Rapid determination of enzyme activities of recombinant human cytochromes P450, human liver microsomes and hepatocytes.
AuthorsGhosal A, Hapangama N, Yuan Y, Lu X, Horne D, Patrick JE, Zbaida S
JournalBiopharm Drug Dispos
PubMed ID14689466
Cytochrome P450 (CYP) substrates that yield fluorescent metabolites were used for rapid screening of drug metabolism activities of 13 recombinant human cytochromes P450, human liver microsomes and human hepatocytes. Reproducible results were obtained using a fluorescent plate reader (CytoFluor) more expediently than those generated using conventional HPLC methods. Typically, results ... More