Influence of the Galloyl Moiety in Tea Catechins on Binding Affinity for Human Serum Albumin

Minoda, Kanako; Ichikawa, Tomoyuki; Katsumata, Tomoharu; Onobori, Kenichi; Mori, Tomohisa; Suzuki, Yukiko; Ishii, Takeshi; Nakayama, Tsutomu

doi:10.3177/jnsv.56.331

Cited by 24 publications

(13 citation statements)

References 25 publications

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“…In contrast, the UF-filtrate (rich in low molecular weight tannins) and single hydrolysable tannins seem to have either no or only a reversible effect in this assay. In line with this observation, the protein binding efficiency of tannins increases with molecular size [26] and the number of galloyl residues [85], [86], suggesting a tighter binding of high molecular weight tannins to target proteins. In addition to interfering with surface proteins, a virucidal activity (e.g.…”

Section: Discussionsupporting

confidence: 67%

Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papillomavirus

et al. 2014

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Antiviral activity has been demonstrated for different tannin-rich plant extracts. Since tannins of different classes and molecular weights are often found together in plant extracts and may differ in their antiviral activity, we have compared the effect against influenza A virus (IAV) of Hamamelis virginiana L. bark extract, fractions enriched in tannins of different molecular weights and individual tannins of defined structures, including pseudotannins. We demonstrate antiviral activity of the bark extract against different IAV strains, including the recently emerged H7N9, and show for the first time that a tannin-rich extract inhibits human papillomavirus (HPV) type 16 infection. As the best performing antiviral candidate, we identified a highly potent fraction against both IAV and HPV, enriched in high molecular weight condensed tannins by ultrafiltration, a simple, reproducible and easily upscalable method. This ultrafiltration concentrate and the bark extract inhibited early and, to a minor extent, later steps in the IAV life cycle and tannin-dependently inhibited HPV attachment. We observed interesting mechanistic differences between tannin structures: High molecular weight tannin containing extracts and tannic acid (1702 g/mol) inhibited both IAV receptor binding and neuraminidase activity. In contrast, low molecular weight compounds (<500 g/mol) such as gallic acid, epigallocatechin gallate or hamamelitannin inhibited neuraminidase but not hemagglutination. Average molecular weight of the compounds seemed to positively correlate with receptor binding (but not neuraminidase) inhibition. In general, neuraminidase inhibition seemed to contribute little to the antiviral activity. Importantly, antiviral use of the ultrafiltration fraction enriched in high molecular weight condensed tannins and, to a lesser extent, the unfractionated bark extract was preferable over individual isolated compounds. These results are of interest for developing and improving plant-based antivirals.

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Section: Discussionsupporting

confidence: 67%

Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papillomavirus

et al. 2014

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“…Polyphenols are also thought to be likely to interact with proteins due to the structural factors of phenolic hydroxyl groups such as their hydrophobicity and hydrogen bonding properties. It has been reported that the binding of proteins and polyphenols produce a water-insoluble complex [ 11 , 12 , 13 , 14 ], and that polyphenols inhibit the toxin activity of staphylococcal proteins [ 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Although there is a report on the binding interaction analysis of staphylococcal enterotoxin B protein and polyphenols [ 22 ], there is no report on the binding interaction analysis of SEA proteins and polyphenols.…”

Section: Introductionmentioning

confidence: 99%

Binding of Catechins to Staphylococcal Enterotoxin A

et al. 2018

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Staphylococcal enterotoxin A (SEA) is a toxin protein, and is the most common cause of staphylococcal food poisoning. Polyphenols, such as catechins, are known to interact with proteins. In this study, we investigated the binding of catechins to SEA using SPR (Biacore), Fourier transform infrared spectroscopy (FT-IR), isothermal titration calorimetry (ITC), and protein-ligand docking. We found that (−)-epigallocatechin gallate (EGCG) could strongly bind to SEA. According to thermodynamic parameters, a negative ΔG indicated that the interaction between EGCG and SEA was spontaneous, and the electrostatic force accompanied by hydrophobic binding forces may play a major role in the binding. Data from Western blot analysis and docking simulation suggest that the hydroxyl group at position 3 of the galloyl group in the catechin structure was responsible for binding affinity with the Y91 of the A-6 region of SEA active sites. Our results provide further understanding of the binding interactions between catechins and SEA, and the inhibition of toxin activities by catechins.

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“…Studies using fluorescence quenching of the single tryptophan found dissociation constants ( K d ) to HSA of 17 μM [9] and 12.5 μM [10], though such studies can only monitor binding close to Sudlow site I and any other binding will be invisible. A study using quartz crystal microbalance found a K d of 4 μM [11]. Two molecular docking studies of EGCG/BSA binding suggested binding near Sudlow site I [8,12], while another fluorescence study backed by modelling [9] suggested that EGCG binds HSA at a single site, probably at Sudlow site I.…”

Section: Introductionmentioning

confidence: 99%

Multi-site binding of epigallocatechin gallate to human serum albumin measured by NMR and isothermal titration calorimetry

Eaton

Williamson

2017

Bioscience Reports

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The affinity of epigallocatechin gallate (EGCG) for human serum albumin (HSA) was measured in physiological conditions using NMR and isothermal titration calorimetry (ITC). NMR estimated the Ka (self-dissociation constant) of EGCG as 50 mM. NMR showed two binding events: strong (n1=1.8 ± 0.2; Kd1 =19 ± 12 μM) and weak (n2∼20; Kd2 =40 ± 20 mM). ITC also showed two binding events: strong (n1=2.5 ± 0.03; Kd1 =21.6 ± 4.0 μM) and weak (n2=9 ± 1; Kd2 =22 ± 4 mM). The two techniques are consistent, with an unexpectedly high number of bound EGCG. The strong binding is consistent with binding in the two Sudlow pockets. These results imply that almost all EGCG is transported in the blood bound to albumin and explains the wide tissue distribution and chemical stability of EGCG in vivo.

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Influence of the Galloyl Moiety in Tea Catechins on Binding Affinity for Human Serum Albumin

Cited by 24 publications

References 25 publications

Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papillomavirus

Tannins from Hamamelis virginiana Bark Extract: Characterization and Improvement of the Antiviral Efficacy against Influenza A Virus and Human Papillomavirus

Binding of Catechins to Staphylococcal Enterotoxin A

Multi-site binding of epigallocatechin gallate to human serum albumin measured by NMR and isothermal titration calorimetry

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