Studies of verapamil binding to human serum albumin by high-performance affinity chromatography

The binding of verapamil to the protein human serum albumin (HSA) was examined by using high-performance affinity chromatography. Many previous reports have investigated the binding of verapamil with HSA, but the exact strength and nature of this interaction (e.g. the number and location of binding sites) is still unclear. In this study, frontal analysis indicated that at least one major binding site was present for R- and S-verapamil on HSA, with estimated association equilibrium constants on the order of 10(4)M(-1) and a 1.4-fold difference in these values for the verapamil enantiomers at pH 7.4 and 37 degrees C. The presence of a second, weaker group of binding sites on HSA was also suggested by these results. Competitive binding studies using zonal elution were carried out between verapamil and various probe compounds that have known interactions with several major and minor sites on HSA. R/S-Verapamil was found to have direct competition with S-warfarin, indicating that verapamil was binding to Sudlow site I (i.e. the warfarin-azapropazone site of HSA). The average association equilibrium constant for R- and S-verapamil at this site was 1.4 (+/-0.1)x10(4)M(-1). Verapamil did not have any notable binding to Sudlow site II of HSA but did appear to have some weak allosteric interactions with l-tryptophan, a probe for this site. An allosteric interaction between verapamil and tamoxifen (a probe for the tamoxifen site) was also noted, which was consistent with the binding of verapamil at Sudlow site I. No interaction was seen between verapamil and digitoxin, a probe for the digitoxin site of HSA. These results gave good agreement with previous observations made in the literature and help provide a more detailed description of how verapamil is transported in blood and of how it may interact with other drugs in the body.

Medienart:

E-Artikel

Erscheinungsjahr:

2008

Erschienen:

2008

Enthalten in:

Zur Gesamtaufnahme - volume:876

Enthalten in:

Journal of chromatography. B, Analytical technologies in the biomedical and life sciences - 876(2008), 1 vom: 01. Dez., Seite 69-75

Sprache:

Englisch

Beteiligte Personen:

Mallik, Rangan [VerfasserIn]
Yoo, Michelle J [VerfasserIn]
Chen, Sike [VerfasserIn]
Hage, David S [VerfasserIn]

Links:

Volltext

Themen:

094ZI81Y45
5Q7ZVV76EI
8DUH1N11BX
CJ0O37KU29
Journal Article
Research Support, N.I.H., Extramural
Serum Albumin
Tamoxifen
Tryptophan
Verapamil
Warfarin

Anmerkungen:

Date Completed 19.02.2009

Date Revised 05.11.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jchromb.2008.10.022

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM184251249