Influence of Human Serum Albumin Glycation on the Binding Affinities for Natural Flavonoids

Abstract

Increasing the degree of glycation in diabetes could affect the ability of plasma proteins in binding to small molecules and active compounds. In this study, the influence of glycation of Human serum albumin (HSA) on the binding affinities for six dietary flavonoids was investigated by fluorescence spectra. Glycated HSA was prepared through incubation with glucose and characterized by several methods to confirm the glycation. It was found that the level of glycation increased with the increasing incubation time. The glycation of HSA increased the binding affinities for flavonoids by 1.40 to 48.42 times, which indicates that modifications caused by the glycation may have different influences on the interactions of flavonoids with HSA at separate binding sites on this protein. These results are valuable for understanding the influence of diabetes on the metabolism of flavonoids and other bioactive small molecules in human body.

Optimization and Development of Albumin–Biopolymer Bioconjugates with Solubility-Improving Properties

“…The appearance of new ICD band(s) serve(s) as clear evidence of the interaction between the host molecule and the ligand [36]: this could be observed for both conjugates. Interestingly, Liu et al revealed that glycated human serum albumin has increased binding affinity to flavonoids, such as apigenin, which could affect the metabolism of these compounds in diabetic patients [37]. This finding can support our study, i.e., the binding affinity (therefore solubility) improving properties of modified albumin to apigenin could be valuable in drug delivery.…”

How Does Glycation Affect Binding Parameters of the Albumin-Gliclazide System in the Presence of Drugs Commonly Used in Diabetes? In Vitro Spectroscopic Study

“…It can be clearly observed that intensity of fluorescence decreased with the glycation of BSA: native BSA-DRUG > g10_BSA-DRUG > g30_BSA-DRUG, indicating changes in the protein's environment induced by glucose attachment. This trend is similar to interactions of gliclazide with glycated albumin, as shown in a previous study, and remains in accordance with results obtained by other researchers, as well as for human serum albumin (HSA) [11,24,25].…”

“…Similar effects and variations, in affinity at comparable levels of glycation, have been noted in recent studies examining the binding of sulfonylureas with glycated HSA both in vitro and in vivo [9,33]. On the other hand, some researchers observed increased K a values upon glycation [25,34]. Such results were obtained for PROTEIN-ATOR-GLICL.…”

The Thiol Group Reactivity and the Antioxidant Property of Human Serum Albumin Are Controlled by the Joint Action of Fatty Acids and Glucose Binding

“…In both studies, glycation of HSA was followed in the presence of FAs. The other studies used a non-physiological molar ratio of HSA:glucose for glycation in the absence of FAs, and the decrease in Trp214 fluorescence was very profound [32]. HSA can be substantially modified by oxidative or carbonyl stress if the stressor concentrations are significantly higher than in the physiological conditions or in an incubation period longer than the half-life of HSA [21,22,32].…”

“…The other studies used a non-physiological molar ratio of HSA:glucose for glycation in the absence of FAs, and the decrease in Trp214 fluorescence was very profound [32]. HSA can be substantially modified by oxidative or carbonyl stress if the stressor concentrations are significantly higher than in the physiological conditions or in an incubation period longer than the half-life of HSA [21,22,32]. However, the mild modification of HSA structure was found in in vivo or in vitro studies when the concentration of stressors was in the pathophysiological range [24,27,33].…”