Chromatographic studies of changes in binding of sulfonylurea drugs to human serum albumin due to glycation and fatty acids

Abstract

This report examines the use of high-performance affinity chromatography as a screening tool for studying the change in binding by sulfonylurea drugs to the protein human serum albumin (HSA) during diabetes. The effects of both the non-enzymatic glycation of HSA and the presence of fatty acids on these interactions were considered using a zonal elution format. It was found that there was significant increase (i.e., 2.7 to 3.6-fold) in the relative retention of several sulfonylurea drugs (i.e., acetohexamide, tolbutamide, glybenclamide and gliclazide) on columns containing normal versus glycated HSA. The addition of various long chain fatty acids to the mobile phase gave the same trend in retention for the tested drugs on both the HSA and glycated HSA columns, generally leading to lower binding. Most of the fatty acids examined produced similar or moderately different relative shifts in retention; however, palmitic acid was found to produce a much larger change in retention on columns containing glycated HSA versus normal HSA under the conditions used in this study.

Chromatographic analysis of the effects of fatty acids and glycation on binding by probes for Sudlow sites I and II to human serum albumin

“…The extent of glycation is known to increase during diabetes, with the amount of glycated HSA increasing by 2- to 5-fold for diabetic patients versus normal individuals [17]. It has been suggested that this type of modification can alter the binding of some drugs or solutes to HSA [18–23]. Another change that can occur during diabetes is an elevation in the levels of fatty acids in serum.…”

“…High-performance affinity chromatography (HPAC) and columns containing normal HSA or glycated HSA were recently used to compare the overall effects of glycation and fatty acids on the binding of HSA with several sulfonylurea drugs [18,19]. Each of these drugs is known to have multisite binding to both normal HSA and glycated HSA and to interact at both Sudlow sites I and II [10,18,19,21,22].…”

“…Each of these drugs is known to have multisite binding to both normal HSA and glycated HSA and to interact at both Sudlow sites I and II [10,18,19,21,22]. The analysis of these systems by HPAC was simplified in Refs.…”

“…The analysis of these systems by HPAC was simplified in Refs. [18,19] by using fatty acid concentrations that were up to 100-fold below the normal levels of the same fatty acids in serum, thus emphasizing the initial, high affinity interactions for these fatty acids with HSA.…”

Affinity Chromatography as a Tool for Quantification of Interactions Between Drug Molecules and Their Protein Targets

“…In turn, addition of organic modifier can accelerate the elution of analyte by disturbing the hydrophobic interactions (Hage & Chen, 2006). It also allows to examine the change in binding of drugs when standard physiological system conditions will be changed as a result of pathological lesions (Basiaga & Hage, 2010).…”