scholarly journals Ifosfamide toxicity to the retina and the possible roles of lecithin and quercetin in albino rats

2018 ◽  
Vol 7 (2) ◽  
pp. 800
Author(s):  
Rehab Ahmed ◽  
Eman Aly ◽  
Sherif Mahmoud ◽  
Sahar Awad ◽  
Gehan Kamal
Keyword(s):  
Oxidative Stress ◽  
Side Effects ◽  
Secondary Structure ◽  
Combined Treatment ◽  
Protein Secondary Structure ◽  
Tail Length ◽  
Albino Rats ◽  
Drug Induced ◽  
Α Helix ◽  
Β Sheet

Background: During cancer chemotherapy, drug-induced oxidative stress can limit therapeutic efficiency and cause a number of side effects. Objectives: Our study aimed to characterize the side effects of an alkylating agent chemotherapy ifosfamide to the retina and if the supplementation of lecithin and or quercetin can diminish its oxidative stress by means of comet assay and FTIR.Methods: Seventy female albino rats divided as control, rats given orally quercetin or lecithin, rats injected with ifosfamide, rats given quercetin or lecithin and in combination of them with ifosfamide injection.Results: Lecithin and quercetin groups indicate a normal comet parameters and distribution of protein secondary structure components content of β-turn, α-helix and β-sheet. After Ifosfamide injection, all comet parameters and β-Turns content were significant increase (p˂0.05) with the same context significant decrease (p˂0.05) of α-helix was observed. Lecithin or quercetin reduces the effect of ifosfamide injection in tail length and percentage tailed DNA. Combined treatment gives more protection against DNA damage. Lecithin role is cleared in returning the normal distribution of β-turn, α-helix, β-sheet and lack of protective effect of quercetin regarding the protein secondary structure of retina was observed.Conclusion: We suggest using lecithin and quercetin in combined treatment to reduce the oxidative stress due to ifosfamide.

Use of synchrotron-based FTIR microspectroscopy to determine protein secondary structures of raw and heat-treated brown and golden flaxseeds: A novel approach

2005 ◽  
Vol 85 (4) ◽  
pp. 437-448 ◽  
Author(s):  
P. Yu ◽  
J. J. McKinnon ◽  
H. W. Soita ◽  
C. R. Christensen ◽  
D. A. Christensen
Keyword(s):  
Secondary Structure ◽  
Matrix Protein ◽  
Protein Secondary Structure ◽  
Secondary Structures ◽  
Heat Processing ◽  
Lower Percentage ◽  
Protein Secondary Structures ◽  
Novel Approach ◽  
Α Helix ◽  
Β Sheet

The objectives of the study were to use synchrotron Fourier transform infrared microspectroscopy (S-FTIR) as a novel approach to: (1) reveal ultra-structural chemical features of protein secondary structures of flaxseed tissues affected by variety (golden and brown) and heat processing (raw and roasted), and (2) quantify protein secondary structures using Gaussian and Lorentzian methods of multi-component peak modeling. By using multi-component peak modeling at protein amide I region of 1700–1620 cm-1, the results showed that the golden flaxseed contained relatively higher percentage of α-helix (47.1 vs. 36.9%), lower percentage of β-sheet (37.2 vs. 46.3%) and higher (P < 0.05) ratio of α-helix to β-sheet than the brown flaxseed (1.3 vs. 0.8). The roasting reduced (P < 0.05) percentage of α-helix (from 47.1 to 36.1%), increased percentage of β-sheet (from 37.2 to 49.8%) and reduced α-helix to β-sheet ratio (1.3 to 0.7) of the golden flaxseed tissues. However, the roasting did not affect percentage and ratio of α-helix and β-sheet in the brown flaxseed tissue. No significant differences were found in quantification of protein secondary structures between Gaussian and Lorentzian methods. These results demonstrate the potential of highly spatially resolved S-FTIR to localize relatively pure protein in the tissue and reveal protein secondary structures at a cellular level. The results indicated relative differences in protein secondary structures between flaxseed varieties and differences in sensitivities of protein secondary structure to the heat processing. Further study is needed to understand the relationship between protein secondary structure and protein digestion and utilization of flaxseed and to investigate whether the changes in the relative amounts of protein secondary structures are primarily responsible for differences in protein availability. Key words: Synchrotron, FTIR microspectrosopy, flaxseeds, intrinsic structural matrix, protein secondary structures, protein nutritive value

scholarly journals Evaluation of protein secondary structure from FTIR spectra improved after partial deuteration

2021 ◽  
Author(s):  
Joëlle De Meutter ◽  
Erik Goormaghtigh
Keyword(s):  
Secondary Structure ◽  
Protein Secondary Structure ◽  
Protein Microarrays ◽  
Ftir Spectra ◽  
Partial Least Square ◽  
Least Square ◽  
Partial Least Square Regression ◽  
Disordered Structures ◽  
Α Helix ◽  
Β Sheet

AbstractFTIR spectroscopy has become a major tool to determine protein secondary structure. One of the identified obstacle for reaching better predictions is the strong overlap of bands assigned to different secondary structures. Yet, while for instance disordered structures and α-helical structures absorb almost at the same wavenumber, the absorbance bands are differentially shifted upon deuteration, in part because exchange is much faster for disordered structures. We recorded the FTIR spectra of 85 proteins at different stages of hydrogen/deuterium exchange process using protein microarrays and infrared imaging for high throughput measurements. Several methods were used to relate spectral shape to secondary structure content. While in absolute terms, β-sheet is always better predicted than α-helix content, results consistently indicate an improvement of secondary structure predictions essentially for the α-helix and the category called “Others” (grouping random, turns, bends, etc.) after 15 min of exchange. On the contrary, the β-sheet fraction is better predicted in non-deuterated conditions. Using partial least square regression, the error of prediction for the α-helix content is reduced after 15-min deuteration. Further deuteration degrades the prediction. Error on the prediction for the “Others” structures also decreases after 15-min deuteration. Cross-validation or a single 25-protein test set result in the same overall conclusions.

scholarly journals Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Ana M. Herrero ◽  
Claudia Ruiz-Capillas
Keyword(s):  
Raman Spectroscopy ◽  
Structural Properties ◽  
Structural Changes ◽  
Protein Secondary Structure ◽  
Lipid Phase ◽  
Α Helix ◽  
Β Sheet ◽  
Shed Light ◽  
Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

scholarly journals (De)stabilization of Alpha-Synuclein Fibrillary Aggregation by Charged and Uncharged Surfactants

2021 ◽  
Vol 22 (22) ◽  
pp. 12509
Author(s):  
Joana Angélica Loureiro ◽  
Stéphanie Andrade ◽  
Lies Goderis ◽  
Ruben Gomez-Gutierrez ◽  
Claudio Soto ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Hydrophobic Interactions ◽  
Neurodegenerative Disorder ◽  
Sodium Dodecyl ◽  
Lewy Bodies ◽  
Alpha Synuclein ◽  
Cetyltrimethylammonium Chloride ◽  
Α Helix ◽  
Β Sheet

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. An important hallmark of PD involves the pathological aggregation of proteins in structures known as Lewy bodies. The major component of these proteinaceous inclusions is alpha (α)-synuclein. In different conditions, α-synuclein can assume conformations rich in either α-helix or β-sheets. The mechanisms of α-synuclein misfolding, aggregation, and fibrillation remain unknown, but it is thought that β-sheet conformation of α-synuclein is responsible for its associated toxic mechanisms. To gain fundamental insights into the process of α-synuclein misfolding and aggregation, the secondary structure of this protein in the presence of charged and non-charged surfactant solutions was characterized. The selected surfactants were (anionic) sodium dodecyl sulphate (SDS), (cationic) cetyltrimethylammonium chloride (CTAC), and (uncharged) octyl β-D-glucopyranoside (OG). The effect of surfactants in α-synuclein misfolding was assessed by ultra-structural analyses, in vitro aggregation assays, and secondary structure analyses. The α-synuclein aggregation in the presence of negatively charged SDS suggests that SDS-monomer complexes stimulate the aggregation process. A reduction in the electrostatic repulsion between N- and C-terminal and in the hydrophobic interactions between the NAC (non-amyloid beta component) region and the C-terminal seems to be important to undergo aggregation. Fourier transform infrared spectroscopy (FTIR) measurements show that β-sheet structures comprise the assembly of the fibrils.

A Preliminary Report on the Use of Clomipramine in General Practice

1975 ◽  
Vol 20 (1_suppl) ◽  
pp. 67-71 ◽  
Author(s):  
L. W. Wootton ◽  
R. I. Bailey
Keyword(s):  
General Practice ◽  
Side Effects ◽  
Combined Treatment ◽  
Clinical Situation ◽  
Illustrative Case ◽  
Case Histories ◽  
Drug Induced ◽  
Practice Population ◽  
History Of ◽  
Continue Therapy

The use of clomipramine in a large suburban general practice is reviewed. Three hundred and fifty patients have been treated to date out of a total practice population of twenty-one thousand. It is argued that phobic anxiety states are much commoner than is normally supposed and that they are usually associated with a history of separation or rejection in childhood. A combined treatment regime is employed for one month thereafter clomipramine alone is used. Side-effects may initially present a problem although they may not all be truly drug induced. Some patients use side-effects to manipulate the clinical situation. However proper interpretative management of side effects can assist the clinicians in persuading patients to continue therapy. Some impressive results have been obtained with clomipramine therapy. Illustrative case histories are provided.

scholarly journals Prion Interaction with Normal Protein in Topological Changing Secondary Structure to Aggregation

2020 ◽  
Vol 9 (2) ◽  
pp. 53
Author(s):  
Yao Yao
Keyword(s):  
Hydrogen Bond ◽  
Secondary Structure ◽  
Amyloid Fibril ◽  
Double Helix ◽  
Β Amyloid ◽  
Structural Analogy ◽  
Β Sheets ◽  
Α Helix ◽  
Dna Double Helix ◽  
Β Sheet

<p>Prion is a protein smaller than virus and it infects host in the absence of nucleic acid. The secondary structure of protein folds incorrectly from α-helices to β-sheets through breaking and re-formation of hydrogen bond. Structural analogy of α-helix and DNA double helix and comparing differences between α-helix and β-sheet show prion's infectivity and propagation. Aggregates of dimers and polymers generate β-amyloid fibril in Alzheimer's disease.</p>

Phospholipid-Specific Conformational Changes in Human Prothrombin upon Binding to Procoagulant Acidic Lipid Membranes

1994 ◽  
Vol 71 (05) ◽  
pp. 596-604 ◽  
Author(s):  
Jogin R Wu ◽  
Barry R Lentz
Keyword(s):  
Secondary Structure ◽  
Conformational Changes ◽  
Lipid Membranes ◽  
Membrane Vesicles ◽  
Scanning Calorimetry ◽  
Domain Organization ◽  
Α Helix ◽  
Β Sheet ◽  
Prothrombin Activation

SummaryThis paper provides evidence to demonstrate that human prothrombin undergoes conformational changes upon binding to procoagulant membranes specifically containing phosphatidylserine (PS). Fourier transform infrared spectroscopy was used to show a slight increase in ordered (α-helix, β-sheet, β-turns) secondary structure upon binding to PS-containing membranes. Thermograms representing prothrombin and prothrombin fragment 1 denaturation were obtained using differential scanning calorimetry. These were analyzed and interpreted in terms of changes in prothrombin domain organization associated with binding to PS-containing membranes. Changes in either secondary structure or domain organization upon binding to negatively-charged phosphatidylglycerol-containing membranes were, if they occurred at all, much less dramatic. The results paralleled results obtained previously with bovine prothrombin (1, 2). The implications of these results in terms of a possible molecular mechanism for the cofactor-like role of platelet membrane vesicles in prothrombin activation are discussed.

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