Kinetic studies of drug-protein interactions by using peak profiling and high-performance affinity chromatography: examination of multi-site interactions of drugs with human serum albumin columns.
Carbamazepine and imipramine are drugs that have significant binding to human serum albumin (HSA), the most abundant serum protein in blood and a common transport protein for many drugs in the body. Information on the kinetics of these drug interactions with HSA would be valuable in understanding the pharmacokinetic behavior of these drugs and could provide data that might lead to the creation of improved assays for these analytes in biological samples. In this report, an approach based on peak profiling was used with high-performance affinity chromatography to measure the dissociation rate constants for carbamazepine and imipramine with HSA. This approach compared the elution profiles for each drug and a non-retained species on an HSA column and control column over a board range of flow rates. Various approaches for the corrections of non-specific binding between these drugs and the support were considered and compared in this process. Dissociation rate constants of 1.7 (±0.2) s(-1) and 0.67 (±0.04) s(-1) at pH 7.4 and 37°C were estimated by this approach for HSA in its interactions with carbamazepine and imipramine, respectively. These results gave good agreement with rate constants that have determined by other methods or for similar solute interactions with HSA. The approach described in this report for kinetic studies is not limited to these particular drugs or HSA but can also be extended to other drugs and proteins.
Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, USA.
Zenghan
Z
Tong
John E
JE
Schiel
Efthimia
E
Papastavros
Corey M
CM
Ohnmacht
Quentin R
QR
Smith
David S
DS
Hage
D002220:Carbamazepine / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002846:Chromatography, Affinity / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007099:Imipramine / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
D055767:Immobilized Proteins; D012709:Serum Albumin; D002220:Carbamazepine; D007099:Imipramine