Myricetin Prevents Fibrillogenesis of Hen Egg White Lysozyme

Abstract

Myricetin is a natural flavonol found in many grapes, berries, fruits, vegetables, and herbs as well as other plants. Recent studies have identified potential antiamyloidogenic activity for this compound. In this study, the kinetics of amyloid fibril formation by hen egg white lysozyme (HEWL) and the antifibril-forming activity of myricetin were investigated. We demonstrate that myricetin significantly inhibits the fibrillation of HEWL and the inhibitory effect is dose-dependent. Interestingly, the inhibitory effect toward HEWL fibrillation was stronger than that exerted by the previously characterized fibril-forming inhibitor quercetin, which has high structural similarity with myricetin. Spectrofluorometric and computational studies suggest that the mechanism underlying the inhibitory action of myricetin at a molecular level is to reduce the population of partially unfolded HEWL intermediates. This action is achieved by the tight binding of myricetin to the aggregation-prone region of the β-domain of HEWL and linking to the relatively stable α-domain, thus resulting in the inhibition of amyloid fibril formation. KEYWORDS: myricetin, lysozyme, amyloid, molecular dynamics simulation, molecular docking ■ INTRODUCTIONAmyloid diseases are characterized by conformational changes of certain proteins, which lead to intracellular or extracellular aggregation, eventually resulting in fibrillar amyloid deposits in the affected tissue. Currently there are approximately 30 extracellular fibril proteins known to be associated with human amyloidosis. 1 The so-called "hereditary non-neuropathic systemic amyloidosis" is associated with two lysozyme variants (I56T and D67H), which were identified in the early 1990s 2 and other naturally occurring amyloidogenic variants (F57I, F57I/ T70N, W64R, and T70N/W112R) discovered more recently. 3−5 The pathological characteristics of these amyloidoses includes the deposition of the full-length protein variants in organs, such as liver, spleen, and kidneys. 2 At present there are still no effective treatments for amyloid diseases such as Alzheimer's disease, systemic amyloidosis, familial amyloid polyneuropathy, and Creutzfeldt-Jakob disease, and all drugs in development that target Alzheimer's disease have failed at various stages of clinical trials. 6 However, the identification and development of small molecules that inhibit fibril formation by amyloidogenic proteins is a promising area of research. 7,8 Among the most promising small-molecule inhibitors, the naturally occurring polyphenols show the most effective antiamyloidogenic activity. 9 A group of polyphenols found in green tea (GTPs) including (−)-epigallocatechin (EGC), (−)-epicatechin gallate (ECG), and (−)-epigallocatechin gallate (EGCG) have been reported as effective inhibitors of alkali-saltinduced fibrillogenesis of hen egg white lysozyme (HEWL) with ECG as the most potent polyphenol. 10 A previous report demonstrated that curcumin can also inhibit the aggregation and formation of amyloid fibrillation of HEWL ...

Inhibition of amyloid fibrillation and cytotoxicity of lysozyme fibrillation products by polyphenols

“…Furthermore, numerous reports have suggested that the antioxidant property of a polyphenol is involved in its anti-amyloidogenic activity [64][65][66]. Given the fact that both RA and Res are potent antioxidants [40,41], a combination of aromatic/hydrophobic interactions and antioxidative properties may contribute to the anti-amyloidogenic activity of the polyphenols [22,36,[67][68][69]. Further work, would be needed to confirm this hypothesis.…”

“…We have previously demonstrated the effectiveness of indole derivatives to diminish HEWL fibrillation and to disaggregate preformed amyloid fibrils [35]. Several naturally occurring polyphenols, including myricetin [36], (−)-epicatechin gallate [37], curcumin and kaempferol [38], have been reported to markedly inhibit HEWL fibril formation. Studies by He et al have indicated that tea catechins polyphenols convert preformed lysozyme fibrils to amorphous aggregates [39].…”

Chelerythrine–lysozyme interaction: spectroscopic studies, thermodynamics and molecular modeling exploration

“…is already a proven model for examining amyloid fibril formation. 75,76 Among them, 9 amino acids are very important and carry the ability of self-fibrillation called K-peptide. 74 Considering this, we compared the chelerythrine binding region to that of the amyloidogenic aggregation prone region.…”

Conditions Governing Food Protein Amyloid Fibril Formation—Part I: Egg and Cereal Proteins

“…Numerous researchers have investigated the inhibition of LYS amyloid formation. This has resulted in a list of compounds that either partially or completely inhibit fibril formation at acidic pH: food constituents such as short‐chain phospholipids (pH 2.0 and 55 °C) (Wang, Hung, Wen, Lin, & Chen, ), curcumin (Liu et al., ; Wang, Liu, & Lee, ) or its water‐soluble derivatives (Wang et al., ), myricetin (He et al., ), the osmolytes proline, hydroxyproline, sarcosine and trimethylamine N‐oxide (Choudhary & Kishore, ), cysteine (Takai et al., ; Wang, Liu, Wu, & Lai, ), glutathione (Wang, Chou, Liu, & Wu, ), carnosine (Wu et al., ), trehalose, magnesium chloride (Chatterjee, Kolli, & Sarkar, ), safranal, crocin (Joloudar et al., ), zinc ions (Ma, Zhang, Wang, & Zhu, ), aroma components (for example, phenyl ethyl alcohol, N,N,N,N’‐tetramethylethylenediamine, or cinnamaldehyde) (Seraj et al., ), rosmarinic acid, resveratrol (Shariatizi, Meratan, Ghasemi, & Nemat‐Gorgani, ), chemicals such as p‐benzoquinone (Lieu et al., ; Wang, Chen, & Hung, ), 4‐aminophenol and 2‐amino‐4‐chlorophenol (Vieira, Figueroa‐Villar, Meirelles, Ferreira, & De Felice, ), tris(2‐carboxyethyl)phosphine (Wang, Liu, & Lu, ), SDS concentrations of at least 0.25 mM (Hung et al., ), nonionic detergents like triton X‐100 and n‐dodecyl‐β‐D‐maltoside (Siposova, Kozar, & Musatov, ), the ionic liquid tetramethyl guanidinium acetate (Kalhor, Kamizi, Akbari, & Heydari, ), clotrimazole (Sarkar, Kumar, & Dubey, ), sodium tetrathionate (Sarkar, Kumar, & Dubey, ), β‐mercaptoethanol (Sarkar et al., ), glycol‐acridines (Vuong et al., ), 2‐acetyl amin‐3‐[4‐(2‐amintgo‐5‐sulfo‐phenyl]‐propionic acid (Maity et al., ), indole, indole 3‐acetic acid, indole 3‐carbinol, indole 3‐propionic acid and tryptophol (Morshedi, Rezaei‐Ghaleh, Ebrahim‐Habibi, Ahmadian, & Nemat‐Gorgani, ), and other components such as melatonin (Wang, Chen, et al., ), glutathione‐covered gold nanoparticles (Antosova et al., ), manganese–salen derivatives (Bahramikia & Yazdanparast, ; Bahramikia, Yazdanparast, & Gheysarzadeh, ), the crowding agents Ficoll 70 and dextran 70 (Ma et al., ), bovine serum albumin and its combination with Ficoll 70 (Zhou, Zhou, Hu, Chen, & Liang, ), and type I collagen (Dubey & Mar, ).…”

“…Numerous researchers have investigated the inhibition of LYS amyloid formation. This has resulted in a list of compounds that either partially or completely inhibit fibril formation at acidic pH: food constituents such as short-chain phospholipids (pH 2.0 and 55°C) (Wang, Hung, Wen, Lin, & Chen, 2011), curcumin (Liu et al, 2012;Wang, Liu, & Lee, 2009) or its water-soluble derivatives (Wang et al, 2018), myricetin (He et al, 2014) Fibrillation of egg and cereal proteins . .…”