Characterization of antibodies against benzo[a]pyrene with thermodynamic and kinetic constants.

Antibodies of a polyclonal antiserum against benzo[a]pyrene were characterized by determining thermodynamic and kinetic constants of the antigen-antibody reaction. Label-free binding assays with optical detection based on reflectometric interference spectroscopy were performed to determine these constants. Different evaluation methods for kinetic measurements were compared. Also, cross-reactivity against two other polycyclic aromatic hydrocarbons, chrysene and pyrene, was checked. The affinity constant between the antibodies and benzo[a]pyrene in homogeneous phase was determined to be K=(5.3+/-0.3)x10(7) M(-1) which was in the middle of the usual range of antibody affinities. The association rate constant for the reaction at the surface was determined to be (3.8+/-0.9)x10(5) M(-1) s(-1), the dissociation rate constant as (9.7+/-0.5)x10(-3) s(-1). Different evaluation methods applied to the kinetic measurements led to the same results. This antiserum would be suitable for the selective determination of benzo[a]pyrene in concentrated samples.

Duke Scholars

Author Tuan Vo-Dinh Biomedical Engineering