Tags

Type your tag names separated by a space and hit enter

Inhibition kinetics of monoclonal antibodies against cytochromes P450.
Drug Metab Dispos. 2002 Jun; 30(6):701-8.DM

Abstract

Monoclonal antibodies (MAbs) inhibitory to individual cytochromes P450 (P450s) are of tremendous utility in identification of P450s responsible for the metabolism of a given drug or drug candidate in pharmaceuticals. In the present study, two inhibitory MAbs against CYP2D6 (MAb(2D6-50,) IgG(2b) and MAb(2D6-184), IgG(2a)) were developed by hybridoma technology to exhibit their high specificity and potency. The MAbs were further employed to assess the quantitative role (47-93%) of CYP2D6 to the metabolism of bufuralol in human liver microsomes from seven donors. Together with the MAb inhibitory to CYP3A4 as previously reported (Mei et al., 1999), the MAbs were used to study the inhibition kinetics of dextromethorphan O-demethylation (CYP2D6), testosterone 6beta-hydroxylation (CYP3A4) and aflatoxin B1 3-hydroxylation (CYP3A4), respectively, with an adequate size of sample measurement. A kinetic model was proposed to fit the experimental observations with three-dimensional nonlinear regression, thereby resulting in a solution of kinetic parameters, i.e., K(I), K(S), V(max), alpha, and beta (changes in K(I) or K(S) and V(max) in the presence of the MAb). As a result, dissociation constants (K(I)) of the MAbs for the enzymes and the maximal inhibition (beta) values for the P450-catalyzed reactions were predicted to have 0.04 to 0.25 microM and > or =94%, respectively. The results have demonstrated that the model can accurately predict the kinetic parameters and provide some insights into the understanding of the mechanism of MAb interaction with P450 enzyme in nature and the applications of the MAbs in qualitative and quantitative identification of P450s involved in drug metabolism.

Authors+Show Affiliations

Department of Drug Metabolism, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12019198

Citation

Mei, Qin, et al. "Inhibition Kinetics of Monoclonal Antibodies Against Cytochromes P450." Drug Metabolism and Disposition: the Biological Fate of Chemicals, vol. 30, no. 6, 2002, pp. 701-8.
Mei Q, Tang C, Lin Y, et al. Inhibition kinetics of monoclonal antibodies against cytochromes P450. Drug Metab Dispos. 2002;30(6):701-8.
Mei, Q., Tang, C., Lin, Y., Rushmore, T. H., & Shou, M. (2002). Inhibition kinetics of monoclonal antibodies against cytochromes P450. Drug Metabolism and Disposition: the Biological Fate of Chemicals, 30(6), 701-8.
Mei Q, et al. Inhibition Kinetics of Monoclonal Antibodies Against Cytochromes P450. Drug Metab Dispos. 2002;30(6):701-8. PubMed PMID: 12019198.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Inhibition kinetics of monoclonal antibodies against cytochromes P450. AU - Mei,Qin, AU - Tang,Cuyue, AU - Lin,Yuh, AU - Rushmore,Thomas H, AU - Shou,Magang, PY - 2002/5/23/pubmed PY - 2002/10/11/medline PY - 2002/5/23/entrez SP - 701 EP - 8 JF - Drug metabolism and disposition: the biological fate of chemicals JO - Drug Metab Dispos VL - 30 IS - 6 N2 - Monoclonal antibodies (MAbs) inhibitory to individual cytochromes P450 (P450s) are of tremendous utility in identification of P450s responsible for the metabolism of a given drug or drug candidate in pharmaceuticals. In the present study, two inhibitory MAbs against CYP2D6 (MAb(2D6-50,) IgG(2b) and MAb(2D6-184), IgG(2a)) were developed by hybridoma technology to exhibit their high specificity and potency. The MAbs were further employed to assess the quantitative role (47-93%) of CYP2D6 to the metabolism of bufuralol in human liver microsomes from seven donors. Together with the MAb inhibitory to CYP3A4 as previously reported (Mei et al., 1999), the MAbs were used to study the inhibition kinetics of dextromethorphan O-demethylation (CYP2D6), testosterone 6beta-hydroxylation (CYP3A4) and aflatoxin B1 3-hydroxylation (CYP3A4), respectively, with an adequate size of sample measurement. A kinetic model was proposed to fit the experimental observations with three-dimensional nonlinear regression, thereby resulting in a solution of kinetic parameters, i.e., K(I), K(S), V(max), alpha, and beta (changes in K(I) or K(S) and V(max) in the presence of the MAb). As a result, dissociation constants (K(I)) of the MAbs for the enzymes and the maximal inhibition (beta) values for the P450-catalyzed reactions were predicted to have 0.04 to 0.25 microM and > or =94%, respectively. The results have demonstrated that the model can accurately predict the kinetic parameters and provide some insights into the understanding of the mechanism of MAb interaction with P450 enzyme in nature and the applications of the MAbs in qualitative and quantitative identification of P450s involved in drug metabolism. SN - 0090-9556 UR - https://www.unboundmedicine.com/medline/citation/12019198/Inhibition_kinetics_of_monoclonal_antibodies_against_cytochromes_P450_ L2 - http://dmd.aspetjournals.org/cgi/pmidlookup?view=long&pmid=12019198 DB - PRIME DP - Unbound Medicine ER -