scholarly journals Complex of EGCG with Cu(II) Suppresses Amyloid Aggregation and Cu(II)-Induced Cytotoxicity of α-Synuclein

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2940 ◽  
Author(s):  
Yilong Teng ◽  
Juan Zhao ◽  
Lulu Ding ◽  
Yu Ding ◽  
Ping Zhou
Keyword(s):  
Pc12 Cells ◽  
Random Coil ◽  
Molar Ratio ◽  
Divalent Metal Ions ◽  
Promising Strategy ◽  
Gallocatechin Gallate ◽  
Dominant Structure ◽  
Β Sheet ◽  
And Oxidative Stress ◽  
Conformation Transition

Accumulation of α-synuclein (α-Syn) is a remarkable pathology for Parkinson’s disease (PD), therefore clearing it is possibly a promising strategy for treating PD. Aberrant copper (Cu(II)) homeostasis and oxidative stress play critical roles in the abnormal aggregation of α-Syn in the progress of PD. It is reported that the polyphenol (−)-epi-gallocatechin gallate (EGCG) can inhibit α-Syn fibrillation and aggregation, disaggregate α-Syn mature fibrils, as well as protect α-Syn overexpressed-PC12 cells against damage. Also, previous studies have reported that EGCG can chelate many divalent metal ions. What we investigate here is whether EGCG can interfere with the Cu(II) induced fibrillation of α-Syn and protect the cell viability. In this work, on a molecular and cellulaire basis, we demonstrated that EGCG can form a Cu(II)/EGCG complex, leading to the inhibition of Cu(II)-induced conformation transition of α-Syn from random coil to β-sheet, which is a dominant structure in α-Syn fibrils and aggregates. Moreover, we found that the mixture of Cu(II) and EGCG in a molar ratio from 0.5 to 2 can efficiently inhibit this process. Furthermore, we demonstrated that in the α-Syn transduced-PC12 cells, EGCG can inhibit the overexpression and fibrillation of α-Syn in the cells, and reduce Cu(II)-induced reactive oxygen species (ROS), protecting the cells against Cu(II)-mediated toxicity.

Effect of Different Post-Treatment on the Morphology, Structure and Property of Electrospun SF Nanofiber Mats

2012 ◽  
Vol 557-559 ◽  
pp. 607-610
Author(s):  
Tao Liu ◽  
Feng Zhang ◽  
Bao Qi Zuo
Keyword(s):  
Water Resistance ◽  
Post Treatment ◽  
Treatment System ◽  
Random Coil ◽  
Structure And Property ◽  
Before And After ◽  
Α Helix ◽  
Nanofiber Mats ◽  
Β Sheet ◽  
Conformation Transition

In this paper, we employed Methanol, 75% Ethanol, 100%Ethanol, and Isopropanol to treat electrospun SF nanofiber mats, and studied the morphology, structure and property of SF nanofiber before and after treatment by means of SEM, and FTIR. While the as-spun SF nanofiber mats consisted of α-helix and random coil, post-treatment of the SF nanofiber resulted in significant increase in β-sheet component and improvement of water resistance of the SF nanofiber mats. This effect was not obvious affected when different post-treatment system was used, but methanol and 75% was more effective in inducing conformation transition from α-helix and random coil to β-sheet.

In situ microscopic studies on the structures and phase behaviors of SF/PEG films using solid-state NMR and Raman imaging

2016 ◽  
Vol 18 (24) ◽  
pp. 16353-16360 ◽  
Author(s):  
Congheng Chen ◽  
Ting Yao ◽  
Sidong Tu ◽  
Weijie Xu ◽  
Yi Han ◽  
...  
Keyword(s):  
Phase Separation ◽  
Solid State Nmr ◽  
Random Coil ◽  
Rich Domain ◽  
Microscopic Studies ◽  
Helix Conformation ◽  
Phase Behaviors ◽  
Protein Rich ◽  
Β Sheet

SF was incompatible with PEG in some extent, and the phase separation took place in their blend film. The conformation of SF in the interface between SF and PEG was changed to the β-sheet, while that in the protein-rich domain remained in the random coil and/or helix conformation.

Influence of Post-Treatment with Methanol Vapor on the Properties of SF/P(LLA-CL) Nanofibrous Scaffolds

2011 ◽  
Vol 236-238 ◽  
pp. 2221-2224
Author(s):  
Kui Hua Zhang ◽  
Xiu Mei Mo
Keyword(s):  
Electrospun Nanofibers ◽  
Random Coil ◽  
Methanol Vapor ◽  
Nanofibrous Scaffolds ◽  
Nanofibrous Structure ◽  
Α Helix ◽  
Β Sheet ◽  
Ideal Method ◽  
C Nmr

In order to improve water-resistant ability silk fibroin (SF) and SF/P(LLA-CL) blended nanofibrous scaffolds for tissue engineering applications, methanol vapor were used to treat electrospun nanofibers. SEM indicated SF and SF/ P(LLA-CL) scaffolds maintained nanofibrous structure after treated with methanol vapor and possessed good water-resistant ability. Characterization of 13C NMR clarified methanol vapor induced SF conformation from random coil or α- helix to β-sheet. Moreover, treated SF/ P (LLA-CL) nanofibrous scaffolds still kept good mechanical properties. Methanol vapor could be ideal method to treat SF and SF/ P(LLA-CL) nanofibrous scaffolds for biomedical applications.

Fabrication and Characterization of Vitamin E TPGS Loaded Silk Fibroin/Hyaluronic Acid Nanofibrous Scaffolds

2013 ◽  
Vol 721 ◽  
pp. 274-277
Author(s):  
Li Li Ji ◽  
Qiao Ling Li ◽  
Zeng Hu Yang ◽  
Wei Jing Hu ◽  
Kui Hua Zhang
Keyword(s):  
Hyaluronic Acid ◽  
Vitamin E ◽  
Silk Fibroin ◽  
Ethanol Vapor ◽  
Random Coil ◽  
Burst Release ◽  
Nanofibrous Scaffolds ◽  
Vitamin E Tpgs ◽  
Polyethylene Glycol 1000 ◽  
Β Sheet

Vitamin E d-alpha-tocopheryl polyethylene glycol 1000 succinate (VE TPGS) loaded silk fibroin (SF)/ hyaluronic acid (HA) nanofibrous scaffolds were fabricated by means of electrospinning to biomimic the natural extracellular matrix. Scanning electronic microscopy (SEM) results indicated that electrospun VE TPGS loaded SF/HA nanofibers were ribbon-shaped, the width of nanofibers decreased slightly with the addition of VE TPGS to SF/HA blended solutions. Fourier transform infrared (FTIR) spectroscopy and Wide-angle X-ray diffraction (WAXD) curves revealed that VE TPGS did not induce SF conformation from random coil to β-sheet. SF conformation converted from random coil to β-sheet after being treated with 75% ethanol vapor. In vitro release studies confirmed VE TPGS had no obvious burst release and present good release behavior.

Effect of curcumin on amyloidogenic property of molten globule-like intermediate state of 2,5-diketo-d-gluconate reductase A

2009 ◽  
Vol 390 (10) ◽  
Author(s):  
Nandini Sarkar ◽  
Abhay Narain Singh ◽  
Vikash Kumar Dubey
Keyword(s):  
Protein Concentration ◽  
Molten Globule ◽  
Molar Ratio ◽  
Amyloid Formation ◽  
Molten Globule State ◽  
Force Microscopy ◽  
Atomic Force ◽  
Sheet Structure ◽  
Amyloid Diseases ◽  
Β Sheet

Abstract We identified a molten globule-like intermediate of 2,5-diketo-d-gluconate reductase A (DKGR) at pH 2.5, which has a prominent β-sheet structure. The molten globule state of the protein shows amyloidogenic property >50 μm protein concentration. Interestingly, a 1:1 molar ratio of curcumin prevents amyloid formation as shown by the Thioflavin-T assay and atomic force microscopy. To the best of our knowledge, this is the first report on amyloid formation by an (α/β)8-barrel protein. The results presented here indicate that the molten globule state has an important role in amyloid formation and potential application of curcumin in protein biotechnology as well as therapeutics against amyloid diseases.

scholarly journals Ent-Peniciherqueinone Suppresses Acetaldehyde-Induced Cytotoxicity and Oxidative Stress by Inducing ALDH and Suppressing MAPK Signaling

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1229
Author(s):  
Taehoon Oh ◽  
Mincheol Kwon ◽  
Jae Sik Yu ◽  
Mina Jang ◽  
Gun-Hee Kim ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pc12 Cells ◽  
Modern Society ◽  
Mapk Signaling ◽  
Heme Oxygenase 1 ◽  
Ros Scavenging ◽  
Protein Levels ◽  
Cellular Reactive Oxygen Species ◽  
Related Stress ◽  
And Oxidative Stress

Studies on ethanol-induced stress and acetaldehyde toxicity are actively being conducted, owing to an increase in alcohol consumption in modern society. In this study, ent-peniciherqueinone (EPQ) isolated from a Hawaiian volcanic soil-associated fungus Penicillium herquei FT729 was found to reduce the acetaldehyde-induced cytotoxicity and oxidative stress in PC12 cells. EPQ increased cell viability in the presence of acetaldehyde-induced cytotoxicity in PC12 cells. In addition, EPQ reduced cellular reactive oxygen species (ROS) levels and restored acetaldehyde-mediated disruption of mitochondrial membrane potential. Western blot analyses revealed that EPQ treatment increased protein levels of ROS-scavenging heme oxygenase-1 and superoxide dismutase, as well as the levels of aldehyde dehydrogenase (ALDH) 1, ALDH2, and ALDH3, under acetaldehyde-induced cellular stress. Finally, EPQ reduced acetaldehyde-induced phosphorylation of p38 and c-Jun N-terminal kinase, which are associated with ROS-induced oxidative stress. Therefore, our results demonstrated that EPQ prevents cellular oxidative stress caused by acetaldehyde and functions as a potent agent to suppress hangover symptoms and alcohol-related stress.

Research on Structure and Property of Silk Fibroin Modified Viscose Fiber

2011 ◽  
Vol 175-176 ◽  
pp. 176-180
Author(s):  
Hui Ying Wu ◽  
Bao Qi Zuo
Keyword(s):  
Amino Acid ◽  
Silk Fibroin ◽  
Amino Acid Content ◽  
Longitudinal Section ◽  
Decomposition Temperature ◽  
Viscose Fiber ◽  
Random Coil ◽  
Wet Strength ◽  
Structure And Property ◽  
Β Sheet

Silk fibroin modified viscose fiber (SFVF) was a new fiber with silken handling and luster, which was produced via adding silk fibroin (SF) during the viscose process. In this paper, a series of testing had been done to study the structure and properties of SFVF. The amino acid content of SFVF was measured by HITACHI-835-50 amino acid tester. The morphology, structure, thermal and mechanical property of SFVF were characterized by SEM, FTIR, DSC and electronic strength tester. The results indicated that SFVF consisted of many kinds of amino acids compared with pure viscose fiber (VF) yarn. The results of SEM showed more continuous multi fine slots existed in the longitudinal section of SFVF than in that of VF, demonstrating that wet permeability and vapor transmission could be enhanced for the SFVF to certain extent. Results from FTIR indicated that the secondary structure of SFVF was mainly β-sheet and random coil, and its absorption peaks were 1616cm-1 and 1644 cm-1 respectively. The DSC curve shown the thermal decomposition temperature of SFVF was about 328.39°C, which was close to that of VF. It suggested that the SF modification had no obvious influence on thermal stability of VF. At last, the dry-strength and wet-strength of SFVF was close to that of VF. Therefore, the application of VF would be expanded with the SF modification.

A comparison of centrifugally-spun and electrospun regenerated silk fibroin nanofiber structures and properties

RSC Advances ◽  
2015 ◽  
Vol 5 (119) ◽  
pp. 98553-98558 ◽  
Author(s):  
Chen Liu ◽  
Jiaqi Sun ◽  
Min Shao ◽  
Bin Yang
Keyword(s):  
Thermal Properties ◽  
Silk Fibroin ◽  
Secondary Structures ◽  
Random Coil ◽  
Structures And Properties ◽  
Regenerated Silk Fibroin ◽  
Centrifugal Spinning ◽  
Β Sheet

Centrifugal spinning converts the conformation of silk fibroin from random coil to β-sheet more easily than electrospinning, which results in fiber differences on secondary structures, orientation and thermal properties.

Low dose simvastatin induces compositional, structural and dynamic changes in rat skeletal extensor digitorum longus muscle tissue

2009 ◽  
Vol 30 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Nihal Ozek Simsek ◽  
Yildirim Sara ◽  
Rustu Onur ◽  
Feride Severcan
Keyword(s):  
Nucleic Acid ◽  
Extensor Digitorum Longus ◽  
Low Dose ◽  
Extensor Digitorum Longus Muscle ◽  
Extensor Digitorum ◽  
Random Coil ◽  
Simvastatin Treatment ◽  
Acid Protein ◽  
Longus Muscle ◽  
Β Sheet

Statins are commonly used drugs in the treatment of hypercholesterolaemia. There are many adverse effects of statins on skeletal muscle, but the underlying mechanisms remain unclear. In the present study, the effects of low dose (20 mg/kg) simvastatin, a lipophilic statin, on rat EDL muscle (extensor digitorum longus muscle) were investigated at the molecular level using FTIR (Fourier-transform infrared) spectroscopy. FTIR spectroscopy allows us rapid and sensitive determination of functional groups belonging to proteins, lipids, carbohydrates and nucleic acids simultaneously. The results revealed that simvastatin treatment induces a significant decrease in lipid, nucleic acid, protein and glycogen content. A significant increase in the lipid/protein and nucleic acid/protein ratios was also obtained with simvastatin treatment. Furthermore, an increase in lipid order and membrane fluidity was detected. A decrease in the bandwidth of the amide I band and shifting of the position of this band to higher frequency values in treated muscle indicates structural changes in proteins. Detailed secondary structure analysis of the amide I band revealed a significant increase in antiparallel and aggregated β-sheet, random coil structure and a significant decrease in β-sheet structure, which indicates protein denaturation.

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