Protein flavonoid interactions with

Flavonoids and other polyphenols can interact with lipids and proteins. The interactions with proteins could be both unspecific or specific, meanwhile the interactions with lipids seems to be rather unspecific, based essentially on physical adsorption. This physical adsorption would mostly depend on the hydrophobic/hydrophilic characteristics of the flavonoid molecule, the number of hydroxyl substituents, and the polymerization degree [Erlejman et al., 2004 Verstraeten et al., 2005, 2003, 2004]. 

Flavonoids can also interact with membrane proteins, such as those functioning as receptors, transporters, channels, and enzymes, and potentially affect their biological activities. A summary of recent advances on the study of flavonoid interactions with plasma membrane proteins is presented in Table 4.2. 

Borbulevych, O.Y. et al.. Lipoxygenase interactions with natural flavonoid, quercetin, reveal a complex with protocatechuic acid in its x-ray structure at 2.1 A resolution. Proteins, 54, 13, 2004. 

Since flavonoids are able to bind to the BDZ binding site of the GABA-A receptor, they might well interact with the BDZ binding site of the mitochondrial permeability transition protein, thereby modulating oxidative stress-induced apoptosis. ... 

Flavonoids, as food components or potential drugs, interact with a wide range of proteins by distinct mechanisms weak and rather unspecific binding of tannins to proline-rich or histi-dine-rich random coils leading to protein precipitation, specific enzyme inhibition, and... 

The final chapter, The Role of the Membrane Actions of Phenothiazines and Flavonoids as Functional Modulators by K. Michalak, O. Wesolowska, N. Motohashi and A. B. Hendrich, presents a very comprehensive review on important biological effects of phenothiazines and flavonoids due to interactions with membrane proteins and the lipid phase of membranes. The discussion includes the influence of these heterocycles on model and natural membranes, modulation of MDR transporters by these heterocycles, and the effects of these hetero cycles on ion channel properties. This review may attract much interest from medicinal and pharmaceutical chemists as well as heterocyclic chemists in the life science fields. 

Very recently, we reviewed the role of membrane action of flavonoids. The structure of flavonoids enables specific interactions with different membrane proteins (multidrug transporters, voltage-gated and chemically activated ion channels) and also nonspecific interactions with the lipid phase of membranes [8]. 

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