Antimicrobial peptide Pup2,due to high cost,shows restricted application value in food preservative,which may be improved by interacting with EGCG,characterized by good functional properties.This study aims to char-ac...Antimicrobial peptide Pup2,due to high cost,shows restricted application value in food preservative,which may be improved by interacting with EGCG,characterized by good functional properties.This study aims to char-acterize a novel antimicrobial peptide-phenolic complex with activity against Staphylococcus aureus and inves-tigate their interaction mechanism.Pup2 and Epigallocatechin-3-gallate(EGCG)exhibited synergistic effects,resulting in a 4-fold and 8-fold decrease in the minimum inhibitory concentration,respectively.Furthermore,the Pup2/EGCG showed a synergistic damaging effect on the bacterial cell wall and membranes.Multi-spectroscopic analyses,which included UV,fluorescence,FTIR,and Raman spectroscopy,showed that Pup2 and EGCG were non-covalently bound through hydrophobic interactions predominantly and assisted by hydrogen bonding.These interactions led to changes in the amino acid microenvironment of Pup2 and alterations in its secondary structure,with theα-helix content increasing from 3%to 26%.DSC similarly confirmed the occurrence of in-teractions and increased peptide stability.Additionally,molecular simulations further demonstrated hydro-phobic interaction and hydrogen bonding were the main binding forces between Pup2 and EGCG,resulting in the formation of a stable complex.This study helps to elucidate the interaction mechanism between antimicrobial peptide Pup2 and EGCG at the molecular level,while highlights the potential application of this complex as a more economical and effective natural antimicrobial preservative.展开更多
HMGB1(high mobility group protein)has been established as a key inflammatory mediator associated with various chronic diseases,particularly in neuroinflammatory pathogenesis.In this work,the potential of chrysin(Chr)/...HMGB1(high mobility group protein)has been established as a key inflammatory mediator associated with various chronic diseases,particularly in neuroinflammatory pathogenesis.In this work,the potential of chrysin(Chr)/apigenin(Api)/luteolin(Lut)as natural functional food ingredients was evaluated on their interactions with HMGB1 through integrated multi-spectroscopic analysis.Surface plasmon resonance(SPR)results of Api and Lut showed the dissociation constants(KD)values of 2.991×10^(-5) M and 3.206×10^(-6) M,respectively,which indicated that the hydroxyl group on the B-ring of flavonoids may impact their binding affinity with HMGB1.Fluorescence spectroscopy and circular dichroism(CD)analyses revealed that the binding of three flavonoids to HMGB1 caused static quenching and significantly altered their spatial conformation,resulting in a reduction in theα-helix content from 60.71±1.30%to Chr(44.24±1.27%),Api(47.52±2.79%)and Lut(49.20±2.07%),respectively.The synchronous and three-dimensional fluorescence spectrum further revealed that these interactions led to the microenvironmental changes in the chromogenic amino acids in HMGB1.Molecular docking experiments indicated that hydrogen bonding was the primary force between the interaction of three flavonoids and HMGB1,and the key amino acids forming the hydrogen bonds included Lys94,Lys95,Asp98,and Arg104 residues.Furthermore,the three flavonoids could mitigate HMGB1-induced neuroinflammation on BV2 microglia cells in the bioassay.Due to the key role of HMGB1 in neuroinflammation and neurological disorders,Chr,Api,and Lut could be applied to improve the treatment of neurological diseases,and they also provided new insights for the development of new dietary supplements of flavonoids.展开更多
In this Letter, we report a combination of non-invasive analysis of the cross-section structure, phase, and chemical composition combining optical coherence tomography(OCT) with spectroscopic methods such as X-ray ana...In this Letter, we report a combination of non-invasive analysis of the cross-section structure, phase, and chemical composition combining optical coherence tomography(OCT) with spectroscopic methods such as X-ray analytical microscope(μ-XRF) and micro-Raman spectroscopy(μ-RS), which allow us to effectively and conveniently identify the colorants used for each color region and the glass-making process of an ancient multicolored stratified glass eye bead. The results reveal that the sophisticated colors of the glass bead arise from the transition metals and chemical compound crystals deliberately added in the same base glass and carefully adjusted by the glass maker to obtain four colors. We also propose and discuss the provenance of the glass bead.It was probably introduced to China through the Northern Silk Road from Egypt or the Eastern Mediterranean areas about 1400 years ago. The combined multi-analytical technique is the promising approach for precious cultural heritage research.展开更多
Quercetin(QU)and its derivatives exhibited good potential in exerting xanthine oxidase(XO)inhibitory activity.Herein,this study comprehensively investigated the interaction mechanism of QU and its derivatives in inhib...Quercetin(QU)and its derivatives exhibited good potential in exerting xanthine oxidase(XO)inhibitory activity.Herein,this study comprehensively investigated the interaction mechanism of QU and its derivatives in inhibiting XO activity by the molecular simulation,inhibition kinetics,ultraviolet-visible spectra,circular dichroism spectrum,and fluorescence spectrum methods.Results showed that glycosylation and hydrogenation of QU were unfavorable for the XO inhibitory activity,while methylation and hydroxylation were beneficial.The types of hydrogen bonds between flavonoids and amino acid residues played an important role in the XO inhibitory activity.Meanwhile,the mixed inhibition type with XO was considered more effective than noncompetitive.Moreover,QU and its derivatives broke the secondary structure and hydrogen networks and quenched the intrinsic fluorescence of XO.The formation of XO-flavonoids complex was endothermic and spontaneous,and H-bonding and van der Waals forces might play a dominant role in this process.Absorption,distribution,metabolism,excretion,and toxicity(ADMET)prediction showed that QU and its derivatives possessed good pharmacokinetic properties.Furthermore,molecular dynamics simulation,inhibition types,ultraviolet-visible spectrum,fluorescence quenching,and thermodynamic parameters could quantitatively evaluate the XO inhibitory effect of flavonoids with different structures.However,there was a deviation in the quantitative evaluation of the XO inhibitory activity of flavonoids by molecular docking and circular dichroism spectrum.展开更多
基金supported by the Yunnan Science and Technology Talents and Platform Program(No.202305AF150132)the National Natural Science Foundation of China(Grant No.32360562)the Young Elite Scientists Sponsorship Program by Yunnan Science and Technology Association.
文摘Antimicrobial peptide Pup2,due to high cost,shows restricted application value in food preservative,which may be improved by interacting with EGCG,characterized by good functional properties.This study aims to char-acterize a novel antimicrobial peptide-phenolic complex with activity against Staphylococcus aureus and inves-tigate their interaction mechanism.Pup2 and Epigallocatechin-3-gallate(EGCG)exhibited synergistic effects,resulting in a 4-fold and 8-fold decrease in the minimum inhibitory concentration,respectively.Furthermore,the Pup2/EGCG showed a synergistic damaging effect on the bacterial cell wall and membranes.Multi-spectroscopic analyses,which included UV,fluorescence,FTIR,and Raman spectroscopy,showed that Pup2 and EGCG were non-covalently bound through hydrophobic interactions predominantly and assisted by hydrogen bonding.These interactions led to changes in the amino acid microenvironment of Pup2 and alterations in its secondary structure,with theα-helix content increasing from 3%to 26%.DSC similarly confirmed the occurrence of in-teractions and increased peptide stability.Additionally,molecular simulations further demonstrated hydro-phobic interaction and hydrogen bonding were the main binding forces between Pup2 and EGCG,resulting in the formation of a stable complex.This study helps to elucidate the interaction mechanism between antimicrobial peptide Pup2 and EGCG at the molecular level,while highlights the potential application of this complex as a more economical and effective natural antimicrobial preservative.
基金supported by the National Nature Science Foundation of China(Grant NO.21302052)the“Program for New Century Excellent Talents in University”for Prof.Jian Zhang(NECT-11-0739).
文摘HMGB1(high mobility group protein)has been established as a key inflammatory mediator associated with various chronic diseases,particularly in neuroinflammatory pathogenesis.In this work,the potential of chrysin(Chr)/apigenin(Api)/luteolin(Lut)as natural functional food ingredients was evaluated on their interactions with HMGB1 through integrated multi-spectroscopic analysis.Surface plasmon resonance(SPR)results of Api and Lut showed the dissociation constants(KD)values of 2.991×10^(-5) M and 3.206×10^(-6) M,respectively,which indicated that the hydroxyl group on the B-ring of flavonoids may impact their binding affinity with HMGB1.Fluorescence spectroscopy and circular dichroism(CD)analyses revealed that the binding of three flavonoids to HMGB1 caused static quenching and significantly altered their spatial conformation,resulting in a reduction in theα-helix content from 60.71±1.30%to Chr(44.24±1.27%),Api(47.52±2.79%)and Lut(49.20±2.07%),respectively.The synchronous and three-dimensional fluorescence spectrum further revealed that these interactions led to the microenvironmental changes in the chromogenic amino acids in HMGB1.Molecular docking experiments indicated that hydrogen bonding was the primary force between the interaction of three flavonoids and HMGB1,and the key amino acids forming the hydrogen bonds included Lys94,Lys95,Asp98,and Arg104 residues.Furthermore,the three flavonoids could mitigate HMGB1-induced neuroinflammation on BV2 microglia cells in the bioassay.Due to the key role of HMGB1 in neuroinflammation and neurological disorders,Chr,Api,and Lut could be applied to improve the treatment of neurological diseases,and they also provided new insights for the development of new dietary supplements of flavonoids.
基金supported by the National Key R&D Program (No. 2019YFC1520203)the National Social Science Foundation of China (NSSF)(No. 18AZD029)。
文摘In this Letter, we report a combination of non-invasive analysis of the cross-section structure, phase, and chemical composition combining optical coherence tomography(OCT) with spectroscopic methods such as X-ray analytical microscope(μ-XRF) and micro-Raman spectroscopy(μ-RS), which allow us to effectively and conveniently identify the colorants used for each color region and the glass-making process of an ancient multicolored stratified glass eye bead. The results reveal that the sophisticated colors of the glass bead arise from the transition metals and chemical compound crystals deliberately added in the same base glass and carefully adjusted by the glass maker to obtain four colors. We also propose and discuss the provenance of the glass bead.It was probably introduced to China through the Northern Silk Road from Egypt or the Eastern Mediterranean areas about 1400 years ago. The combined multi-analytical technique is the promising approach for precious cultural heritage research.
基金financial support of the Key Research and Development Program of Xinjiang Autonomous Region(2022B02026-5)the China National Natural Science Foundation(32302117)Science and Technology Program of Guizhou Province(Qian Ke He Cheng Guo[2024]052)。
文摘Quercetin(QU)and its derivatives exhibited good potential in exerting xanthine oxidase(XO)inhibitory activity.Herein,this study comprehensively investigated the interaction mechanism of QU and its derivatives in inhibiting XO activity by the molecular simulation,inhibition kinetics,ultraviolet-visible spectra,circular dichroism spectrum,and fluorescence spectrum methods.Results showed that glycosylation and hydrogenation of QU were unfavorable for the XO inhibitory activity,while methylation and hydroxylation were beneficial.The types of hydrogen bonds between flavonoids and amino acid residues played an important role in the XO inhibitory activity.Meanwhile,the mixed inhibition type with XO was considered more effective than noncompetitive.Moreover,QU and its derivatives broke the secondary structure and hydrogen networks and quenched the intrinsic fluorescence of XO.The formation of XO-flavonoids complex was endothermic and spontaneous,and H-bonding and van der Waals forces might play a dominant role in this process.Absorption,distribution,metabolism,excretion,and toxicity(ADMET)prediction showed that QU and its derivatives possessed good pharmacokinetic properties.Furthermore,molecular dynamics simulation,inhibition types,ultraviolet-visible spectrum,fluorescence quenching,and thermodynamic parameters could quantitatively evaluate the XO inhibitory effect of flavonoids with different structures.However,there was a deviation in the quantitative evaluation of the XO inhibitory activity of flavonoids by molecular docking and circular dichroism spectrum.
