Monoclonal antibody-directed radioimmunoassay of specific cytochromes P-450.

Song, Byeong Jun; Fujino, Toyomi; Park, S S; Friedman, Fred K.; Gelboin, H V

doi:10.1016/s0021-9258(17)43417-x

Cited by 30 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to kinetically distinguish individual microsomal P450s, we next sought to evaluate the influence of specific P450 effectors on CO binding kinetics. Anti-P450 MAbs are an excellent effector for such studies and have proven useful for characterizing individual P450s in the presence of multiple microsomal P450s employing immunoassay (Song et al, 1984;Cheng et al, 1984;Robinson et al, 1989;Lorr et al, 1989), inhibition of P450-catalyzed activity (Fujino et al, 1984;Friedman et al, 1985b;Pelkonen et al, 1986;Pasanen et al, 1987), and substrate binding assays (Omata & Friedman, 1992a;Tsokos et al, 1992). Another class of effectors are P450 substrates which selectively bind certain forms of P450.…”

Section: Resultsmentioning

confidence: 99%

Kinetics of CO Binding to Cytochromes P450 in the Endoplasmic Reticulum

Koley¹,

Robinson²,

Markowitz³

et al. 1994

Biochemistry

View full text Add to dashboard Cite

The kinetics of CO binding to cytochromes P450 in rat liver microsomes were examined using the flash photolysis technique. Modulation of the kinetics by P450 form-specific effectors such as anti-P450 monoclonal antibodies and substrates was used to elucidate the kinetic behavior of individual P450s within the endoplasmic reticulum. The problem of attributing a kinetic parameter to a single P450 in the presence of multiple microsomal P450s was overcome with a difference method that employs the difference of the kinetic profiles obtained in the presence and absence of a P450 effector. Applying this approach to study the conformation/dynamics of P450 2B1 in microsomes from phenobarbital-treated rats revealed that the substrate benzphetamine enhances while testosterone inhibits the rate of CO binding to this P450. Similar experiments with P450 1A1 in microsomes from 3-methylcholanthrene-treated rats showed that the substrate benzo[a]pyrene accelerates CO binding. These results show that the access channel between solvent and heme in the P450 interior can be altered in a substrate- and P450-dependent manner to either hinder or facilitate CO diffusion to the heme iron. These results also demonstrate that analytical difference methods may be employed to characterize the conformation of individual P450s in their native membrane environment in the endoplasmic reticulum.

show abstract

Section: Resultsmentioning

confidence: 99%

Kinetics of CO Binding to Cytochromes P450 in the Endoplasmic Reticulum

Koley¹,

Robinson²,

Markowitz³

et al. 1994

Biochemistry

View full text Add to dashboard Cite

show abstract

“…Monoclonal antibodies have proven useful in several different phases of cytochrome P-450 research (Park et al, 1980P-450 research (Park et al, , 1982aP-450 research (Park et al, ,b, 1984Boobis et al, 1981;Fujino et al, 1982Fujino et al, , 1984Friedman et al, 1983Friedman et al, , 1985aCheng et al, 1984a;Reubi et al, 1984;Song et al, 1984Song et al, , 1985. In this study six cytochromes P-450 were purified to electrophoretic homogeneity from different tissues and species by a simple MAb-directed immunopurification procedure.…”

Section: Discussionmentioning

confidence: 93%

“…This report further demonstrates the utility of MAbs in different phases of cytochrome P-450 research. MAbs have been previously utilized in phenotyping cytochrome P-450 dependent catalytic activities (Fujino et al, 1982(Fujino et al, , 1984 and in radioimmunoassay (Song et al, 1984(Song et al, , 1985 and immunopurification (Friedman et al, 1983(Friedman et al, , 1985bCheng et al, 1984a). Thus, the MAb-directed methodologies are very powerful tools both for analysis of cytochromes P-450 and for development of an epitope-based classification system for these isozymes.…”

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

“…Monoclonal antibodies (MAbs)1 have recently been introduced as a tool for the study of cytochrome P-450 multiplicity (Park et al, 1980(Park et al, , 1982a(Park et al, ,b, 1984Boobis et al, 1981;Reubi et al, 1984). In our laboratory, we have prepared panels of MAbs to a variety of cytochromes P-450 (Park et al, 1980(Park et al, , 1982a(Park et al, ,b, 1984. We have previously reported on the use of MAbs in phenotyping cytochrome P-450 dependent catalytic activities in tissues from humans (Fujino et al, 1982;Friedman et al, 1985a) and animals (Fujino et al, 1984), in developing radioimmunoassays for cytochrome P-450 (Song et al, 1984(Song et al, , 1985, and for immunopurification of cytochromes P-450 from different animal tissues (Friedman et al, 1983;Cheng et al, 1984a).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Amino-terminal sequence and structure of monoclonal antibody-immunopurified cytochromes P 450

Cheng¹,

Park²,

Krutzsch³

et al. 1986

Biochemistry

View full text Add to dashboard Cite

Six hepatic cytochromes P-450 were isolated from 3-methylcholanthrene-treated animals by immunopurification with monoclonal antibodies. The purified cytochromes P-450 include 57- and 56-kDa polypeptides from Sprague-Dawley rats, 57- and 56-kDa polypeptides from C57BL/6 mice, a 56-kDa polypeptide from DBA/2 mice, and a 53-kDa polypeptide from guinea pigs. These isozymes were structurally compared by peptide mapping using both sodium dodecyl sulfate--polyacrylamide gel electrophoresis and high-pressure liquid chromatography and by amino acid and NH2-terminal sequence analyses. The 57-kDa polypeptides from rats and mice have similar but nonidentical peptide maps and amino acid compositions and are about 80% homologous in their NH2-terminal amino acid sequence. The 56-kDa polypeptides from rats and both mice strains have very similar peptide maps and amino acid compositions and identical NH2-terminal sequences. The NH2-terminal sequence of the mice 56-kDa polypeptides corresponds to that reported for the mouse P1-450 isozyme except that we identified two additional residues, proline and serine, at the NH2 terminus in the 57-kDa polypeptide from C57BL/6 mice that were not deduced from the cDNA sequence of the mouse P1-450 isozyme. The guinea pig 53-kDa polypeptide has a distinct peptide map relative to the other polypeptides studied and an NH2-terminal sequence with only partial homology to the 56- and 57-kDa polypeptides from rats and mice. This report shows the varying degree of structural relatedness among the isozymes examined and demonstrates the suitability and advantage of immunopurified cytochromes P-450 for sequencing and structural studies.

show abstract