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BioAssay: AID 404513

Binding affinity to human serum albumin by fluorescence quenching measurement

As one of the natural polyphenols, resveratrol possesses hydroxyl substituted trans-stilbene structure and exerts impact on health by inhibiting multiple human enzymes, such as cyclooxygenase, F1 ATPase, and tyrosinase. Resveratrol has to be bound by human serum albumin (HSA) to keep a high concentration in serum, since its solubility is low in water. To improve water solubility and more ..
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 Tested Compounds
 Tested Compounds
All(5)
 
 
Unspecified(5)
 
 
 Tested Substances
 Tested Substances
All(5)
 
 
Unspecified(5)
 
 
 Related BioAssays
 Related BioAssays
AID: 404513
Data Source: ChEMBL (552542)
Depositor Category: Literature, Extracted
BioAssay Version:
Deposit Date: 2010-05-26
Modify Date: 2014-05-14

Data Table ( Complete ):           All
Target
Sequence: RecName: Full=Serum albumin; Flags: Precursor
Description ..   
Protein Family: ALBUMIN
Comment ..   

Gene:ALB     Related Protein 3D Structures     More BioActivity Data..
Tested Compounds:
Description:
Title: Design, synthesis and spectroscopic studies of resveratrol aliphatic acid ligands of human serum albumin.

Abstract: As one of the natural polyphenols, resveratrol possesses hydroxyl substituted trans-stilbene structure and exerts impact on health by inhibiting multiple human enzymes, such as cyclooxygenase, F1 ATPase, and tyrosinase. Resveratrol has to be bound by human serum albumin (HSA) to keep a high concentration in serum, since its solubility is low in water. To improve water solubility and bioavailability, two resveratrol aliphatic acids and their esters have been designed and synthesized. The solubilities of the resveratrol and its derivatives have been measured using a standard procedure. The two aliphatic acids showed better solubilities in pure water and phosphate buffer (pH 7). The binding affinities of resveratrol derivatives for HSA were also measured, and the drug-protein interaction mechanism was investigated using fluorescence, UV-vis, and NMR spectroscopies. Interestingly, resveratrol hexanoic acid (5) was found to be a much better ligand (K(a)=(6.70+/-0.10)x10(6) M(-1)) for HSA than resveratrol (K(a)=(1.64+/-0.07)x10(5) M(-1)), and there was 41-fold improvement for the binding affinity. It was the first time that the increase of fluorescence of resveratrol moiety was observed during the binding to HSA, suggesting that 5 should be bound tightly by HSA. The UV-vis absorption spectroscopy revealed a maximum absorption shift from 318 to 311 nm with decreasing intensity by 20% upon complexation, suggesting that the pi-pi conjugation of the stilbene structure was impaired during the binding. Although HSA was reported to have only one binding site for resveratrol, the Job's and molar ratio plots suggested that HSA should bind two molecules of 5. NMR study suggested that phenyl group (B ring) in the center of the molecule of 5 should be involved in the pi-pi stacking interactions with HSA aromatic amino acid residues. Molecular geometry calculation of 5 with Spartan software showed that the stilbene structure had two conformers, orthogonal and planar ones. The former (E=-1.432 KJ/mol) was more stable than the latter (E=-0.128 KJ/mol), suggesting that the former should be the conformer of 5 in the complexation with HSA.
(PMID: 18499462)
Categorized Comment
Assay Type: ADME

Assay Data Source: Scientific Literature

BAO: Assay Format: biochemical format

Target Type: Target is a single protein chain

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Ka activity commentKa activity commentString
2Ka standard flagKa standard flagInteger
3Ka qualifierKa qualifierString
4Ka published valueKa published valueFloat10'5/M
5Ka standard valueKa standard valueFloatM-1

Data Table (Concise)
Classification
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