title: A biochromatographic framework to evaluate the calcium effect on the antihypertensive molecule-human serum albumin binding.
abstract: The Ca(2+) cation effect on the antihypertensive molecule binding on human serum albumin (HSA) was studied by biochromatography. The thermodynamic parameters corresponding to this binding were determined for a wide range of Ca(2+) concentration (x). For the two antihypertensive molecules under study, their binding to HSA can be divided into two Ca(2+) cation concentration regions due to a HSA phase transition. This result was confirmed by an enthalpy-entropy investigation. For a low x value (below x(c)=1.6 mmol l(-1)), the HSA cavity was in an ordered solid-like state leading to an increase in the interactions between the antihypertensive drugs and the HSA cavity and consequently, a solute-HSA affinity increase. For x above x(c), the HSA cavity was in a disordered solid-like state, implying a decrease in the antihypertensive drug-HSA binding.
authors.affiliation: Equipe des Sciences Séparatives et Biopharmaceutiques (2SB), Laboratoire de Chimie Analytique, Faculté Médecine Pharmacie, Univ. de Franche-Comte, Place Saint-Jacques, Besançon 25030, Cedex, France.
authors.forename: Claire
authors.initials: C
authors.lastname: André
authors.forename: Mireille
authors.initials: M
authors.lastname: Thomassin
authors.forename: Catherine
authors.initials: C
authors.lastname: Guyon
authors.forename: Tong-Thanh
authors.initials: TT
authors.lastname: Truong
authors.forename: Yves-Claude
authors.initials: YC
authors.lastname: Guillaume
mesh_terms: D000959:Antihypertensive Agents / Q000032:analysis / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004110:Diltiazem / Q000032:analysis / Q000378:metabolism; D006801:Humans; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D012709:Serum Albumin / Q000032:analysis / Q000378:metabolism*; D014700:Verapamil / Q000032:analysis / Q000378:metabolism
chemical_list: D000959:Antihypertensive Agents; D012709:Serum Albumin; D014700:Verapamil; D004110:Diltiazem; D002118:Calcium