共查询到20条相似文献，搜索用时 203 毫秒
1.
Michele Vitali Valentina Rigamonti Antonino Natalello Barbara Colzani Svetlana Avvakumova Stefania Brocca Carlo Santambrogio Joanna Narkiewicz Giuseppe Legname Miriam Colombo Davide Prosperi Rita Grandori 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(7):1556-1564
Background
Protein-nanoparticle (NP) interactions dictate properties of nanoconjugates relevant to bionanotechnology. Non-covalent adsorption generates a protein corona (PC) formed by an inner and an outer layer, the hard and soft corona (HC, SC). Intrinsically disordered proteins (IDPs) exist in solution as conformational ensembles, whose response to the presence of NPs is not known.Methods
Three IDPs (α-casein, Sic1 and α-synuclein) and lysozyme are compared, describing conformational properties inside HC on silica NPs by circular dichroism (CD) and Fourier-transform infrared (FTIR) spectroscopy.Results
IDPs inside HC are largely unstructured, but display small, protein-specific conformational changes. A minor increase in helical content is observed for α-casein and α-synuclein, reminiscent of membrane effects on α-synuclein. Frozen in their largely disordered conformation, bound proteins do not undergo folding induced by dehydration, as they do in their free forms. While HC thickness approaches the hydrodynamic diameter of the protein in solution for lysozyme, it is much below the respective values for IDPs. NPs boost α-synuclein aggregation kinetics in a dose-dependent manner.Conclusions
IDPs maintain structural disorder inside HC, experiencing minor, protein-specific, induced folding and stabilization against further conformational transitions, such as formation of intermolecular beta-sheets upon dehydration. The HC is formed by a single layer of protein molecules. SC likely plays a key role stabilizing amyloidogenic α-synuclein conformers.General significance
Protein-NP interactions can mimic those with macromolecular partners, allowing dissection of contributing factors by rational design of NP surfaces. Application of NPs in vivo should be carefully tested for amyloidogenic potential. 相似文献2.
Phelippe do Carmo-Gonçalves Eduardo Coelho-Cerqueira Juliana R. Cortines Theo Luiz Ferraz de Souza Luciana Romão Cristian Follmer 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2835-2845
Background
Salsolinol (SALSO), a product from the reaction of dopamine (DA) with acetaldehyde, is found increased in dopaminergic neurons of Parkinson's disease (PD) patients. The administration of SALSO in rats causes myenteric neurodegeneration followed by the formation of deposits of the protein α-synuclein (aS), whose aggregation is intimately associated to PD.Methods
NMR, isothermal titration calorimetry and MS were used to evaluate the interaction of SALSO with aS. The toxicity of SALSO and in vitro-produced aS-SALSO species was evaluated on mesencephalic primary neurons from mice.Results
SALSO, under oxidative conditions, stabilizes the monomeric state besides a minor population of oligomers of aS, resulting in a strong inhibition of the fibrillation process. SALSO does not promote any chemical modification of the protein. Instead, the interaction of SALSO with aS seems to occur via hydrophobic effect, likely mediated by the NAC (non-amyloid component) domain of the protein. aS-SALSO species were found to be innocuous on primary neurons, while SALSO alone induces apoptosis via caspase-3 activation. Importantly, exogenous aS monomer was capable of protecting neurons against SALSO toxicity irrespective whether the protein was co-administered with SALSO or added until 2?h after SALSO, as evidenced by DAPI and cleaved-caspase 3 assays. Similar protective action of aS was found by pre-incubating neurons with aS before the administration of SALSO.Conclusions
Interaction of SALSO with aS leads to the formation of fibril-incompetent and innocuous adducts. SALSO toxicity is attenuated by aS monomer.Significance
aS could exhibit a protective role against the neurotoxic effects of SALSO in dopaminergic neuron. 相似文献3.
Anne M. Reiner Felix Schmidt Sergey Ryazanov Andrei Leonov Daniel Weckbecker Andreas A. Deeg Christian Griesinger Armin Giese Wolfgang Zinth 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):800-807
Background
Recently diphenyl-pyrazole (DPP) compounds and especially anle138b were found to reduce the aggregation of α-synuclein or Tau protein in vitro as well as in a mouse model of neurodegenerative diseases [1,2]. Direct interaction of the DPPs with the fibrillar structure was identified by fluorescence spectroscopy. Thereby a strong dependence of the fluorescence on the surroundings could be identified [3].Methods
Stationary and time-resolved emission experiments were performed on DPP compounds substituted by different halogens.Results
The compounds reveal a pronounced dependence of the fluorescence on the surrounding solvent. In non-polar solvents they show strong emission in the blue part of the spectrum while in polar and proton donating solvents, such as water or acetic acid a dual fluorescence can be observed where a red-shifted emission points to a charge transfer in the excited state with large dipole moment. Non-radiative processes including photochemical reactions are observed for DPP substituted with heavy halogens. Upon binding of anle138b and its derivatives to protein fibrils in aqueous buffer, strong enhancement of the fluorescence at short wavelengths is found.Conclusion
The investigations of the DPPs in different surroundings lead to a detailed model of the fluorescence characteristics. We propose a model for the binding in fibrils of different proteins, where the DPP is located in a hydrophobic groove independent of the specific sequence of the amino acids.General significance
These investigations characterize the binding site of the DPP anle138b in protein aggregates and contribute to the understanding of the therapeutic mode of action of this compound. 相似文献4.
Danfeng Shi Shuangyan Zhou Xuewei Liu Chenxi Zhao Huanxiang Liu Xiaojun Yao 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):576-588
Background
The inhibitors blocking the interaction between programmed cell death protein 1(PD-1) and programmed death-ligand 1(PD-L1) can activate the immune response of T cell and eliminate cancer cells. The crystallographic studies have provided structural insights of the interactive interfaces between PD-L1 and its protein ligands. However, the hotspot residues on PD-L1 as well as structural and energetic basis for different protein ligands still need to be further investigated.Methods
Molecular modeling methods including molecular dynamics simulation, per-residue free energy decomposition, virtual alanine scanning mutagenesis and residue-residue contact analysis were used to qualitatively and quantitatively analyze the interactions between PD-L1 and different protein ligands.Results
The results of virtual alanine scanning mutagenesis suggest that Y56, Q66, M115, D122, Y123, R125 are the hotspot residues on PD-L1. The residue-residue contact analysis further shows that PD-1 interacts with PD-L1 mainly by F and G strands while monoclonal antibodies like avelumab and BMS-936559 mainly interact with PD-L1 by CDR2 and CDR3 loops of the heavy chain.Conclusions
A structurally similar β-hairpin peptide with 13 or 14 residues was extracted from each protein ligand and these β-hairpin peptides were found tightly binding to the putative hotspot residues on PD-L1.General significance
This study recognizes the hotspot residues on PD-L1 and uncovers the common structural and energetic basis of different protein ligands binding to PD-L1. These results will be valuable for the design of small molecule or peptide inhibitors targeting on PD-L1. 相似文献5.
Timur A. Mukhametzyanov Igor A. Sedov Boris N. Solomonov Christoph Schick 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(9):2024-2030
Background
Protein denaturation is often studied using differential scanning calorimetry (DSC). However, conventional instruments are limited in the temperature scanning rate available. Fast scanning calorimetry (FSC) provides an ability to study processes at much higher rates while using extremely small sample masses [ng]. This makes it a very interesting technique for protein investigation.Methods
A combination of conventional DSC and fast scanning calorimeters was used to study denaturation of lysozyme dissolved in glycerol. Glycerol was chosen as a solvent to prevent evaporation from the micro-sized samples of the fast scanning calorimeter.Results
The lysozyme denaturation temperatures in the range of scanning rates from 5?K/min to ca. 500,000?K/min follow the Arrhenius law. The experimental results for FSC and conventional DSC fall into two distinct clusters in a Kissinger plot, which are well approximated by two parallel straight lines.Conclusions
The transition temperatures for the unfolding process measured on fast scanning calorimetry sensor are significantly lower than what could be expected from the results of conventional DSC using extrapolation to high scanning rates. Evidence for the influence of the relative surface area on the unfolding temperature was found.General significance
For the first time, fast scanning calorimetry was employed to study protein denaturation with a range of temperature scanning rates of 5 orders of magnitude. Decreased thermal stability of the micro-sized samples on the fast scanning calorimeter raise caution over using bulk solution thermal stability data of proteins for applications where micro-sized dispersed protein solutions are used, e.g., spray drying. 相似文献6.
Esraa Haj Yelena Losev V. Guru KrishnaKumar Edward Pichinuk Hamutal Engel Avi Raveh Ehud Gazit Daniel Segal 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(7):1565-1575
Background
Alzheimer's disease (AD) is the most common neurodegenerative disorder which is characterized by the deposits of intra-cellular tau protein and extra-cellular amyloid-β (Aβ) peptides in the human brain. Understanding the mechanism of protein aggregation and finding compounds that are capable of inhibiting its aggregation is considered to be highly important for disease therapy.Methods
We used an in vitro High-Throughput Screening for the identification of potent inhibitors of tau aggregation using a proxy model; a highly aggregation-prone hexapeptide fragment 306VQIVYK311 derived from tau. Using ThS fluorescence assay we screened a library of 2401 FDA approved, bio-active and natural compounds in attempt to find molecules which can efficiently modulate tau aggregation.Results
Among the screened compounds, palmatine chloride (PC) alkaloid was able to dramatically reduce the aggregation propensity of PHF6 at sub-molar concentrations. PC was also able to disassemble preformed aggregates of PHF6 and reduce the amyloid content in a dose-dependent manner. Insights obtained from MD simulation showed that PC interacted with the key residues of PHF6 responsible for β-sheet formation, which could likely be the mechanism of inhibition and disassembly. Furthermore, PC could effectively inhibit the aggregation of full-length tau and disassemble preformed aggregates.Conclusions
We found that PC possesses “dual functionality” towards PHF6 and full-length tau, i.e. inhibit their aggregation and disassemble pre-formed fibrils.General significance
The “dual functionality” of PC is valuable as a disease modifying strategy for AD, and other tauopathies, by inhibiting their progress and reducing the effect of fibrils already present in the brain. 相似文献7.
Manuela Leri Reiner Oropesa-Nuñez Claudio Canale Sara Raimondi Sofia Giorgetti Elena Bruzzone Vittorio Bellotti Massimo Stefani Monica Bucciantini 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(6):1432-1442
Background
Many data highlight the benefits of the Mediterranean diet and its main lipid component, extra-virgin olive oil (EVOO). EVOO contains many phenolic compounds that have been found effective against several aging- and lifestyle-related diseases, including neurodegeneration. Oleuropein, a phenolic secoiroid glycoside, is the main polyphenol in the olive oil. It has been reported that the aglycone form of Oleuropein (OleA) interferes in vitro and in vivo with amyloid aggregation of a number of proteins/peptides involved in amyloid, particularly neurodegenerative, diseases avoiding the growth of toxic oligomers and displaying protection against cognitive deterioration.Methods
In this study, we carried out a cellular and biophysical study on the relationships between the effects of OleA on the aggregation and cell interactions of the D76N β2-microglobulin (D76N b2m) variant associated with a familial form of systemic amyloidosis with progressive bowel dysfunction and extensive visceral amyloid deposits.Results
Our results indicate that OleA protection against D76N b2m cytotoxicity results from i) a modification of the conformational and biophysical properties of its amyloid fibrils; ii) a modification of the cell bilayer surface properties of exposed cells.Conclusions
This study reveals that OleA remodels not only D76N b2m aggregates but also the cell membrane interfering with the misfolded proteins-cell membrane association, in most cases an early event triggering amyloid–mediated cytotoxicity.General significance
The data provided in the present article focus on OleA protection, featuring this polyphenol as a promising plant molecule useful against amyloid diseases. 相似文献8.
Huan He Juan Xu Wen Xie Qing-Lian Guo Feng-Lei Jiang Yi Liu 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):501-512
Background
CDK6 is considered as a highly validated anticancer drug target due to its essential role in regulating cell cycle progression at G1 restriction point. Activation of CDK6 requires the phosphorylation of Thr177 on A-loop, but the structural insights of the activation mechanism remain unclear.Methods
Herein, all-atoms molecular dynamics (MD) simulations were used to study the effects of Thr177 phosphorylation on the dynamic structure of CDK6-Vcyclin complex.Results
MD results indicated that the free energy barrier of the transition from open to closed state decreased ~ 47.2% after Thr177 phosphorylation. Key steps along the state transition process were obtained from a cluster analysis. Binding preference of ten different inhibitors to open or closed state were also investigated through molecular docking along with MD simulations methods.Conclusions
Our results indicated that Thr177 phosphorylation increased the flexibility around the ATP-binding pocket. The transition of the ATP-binding pocket between open and closed states should be considered for understanding the binding of CDK6 inhibitors.General significance
This work could deepen the understanding of CDKs activation mechanism, and provide useful information for the discovery of new CDKs inhibitors with high affinity and specificity. 相似文献9.
Andrea Pica Serena Leone Rocco Di Girolamo Federica Donnarumma Alessandro Emendato Michele Fortunato Rega Antonello Merlino Delia Picone 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):808-815
Background
MNEI and its variant Y65R-MNEI are sweet proteins with potential applications as sweeteners in food industry. Also, they are often used as model systems for folding and aggregation studies.Methods
X-ray crystallography was used to structurally characterize Y65R-MNEI at five different pHs, while circular dichroism and fluorescence spectroscopy were used to study their thermal and chemical stability. ThT assay and AFM were used for studying the kinetics of aggregation and morphology of the aggregates.Results
Crystal structures of Y65R-MNEI revealed the existence of a dimer in the asymmetric unit, which, depending on the pH, assumes either an open or a closed conformation. The pH dramatically affects kinetics of formation and morphology of the aggregates: both MNEI and Y65R-MNEI form fibrils at acidic pH while amorphous aggregates are observed at neutral pH.Conclusions
The mutation Y65R induces structural modifications at the C-terminal region of the protein, which account for the decreased stability of the mutant when compared to MNEI. Furthermore, the pH-dependent conformation of the Y65R-MNEI dimer may explain the different type of aggregates formed as a function of pH.General significance
The investigation of the structural bases of aggregation gets us closer to the possibility of controlling such process, either by tuning the physicochemical environmental parameters or by site directed mutagenesis. This knowledge is helpful to expand the range of stability of proteins with potential industrial applications, such as MNEI and its mutant Y65R-MNEI, which should ideally preserve their structure and soluble state through a wide array of conditions. 相似文献10.
Sumangala Shetty Paul R. Copeland 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(11):2506-2510
Background
Selenoprotein synthesis requires the reinterpretation of a UGA stop codon as one that encodes selenocysteine (Sec), a process that requires a set of dedicated translation factors. Among the mammalian selenoproteins, Selenoprotein P (SELENOP) is unique as it contains a selenocysteine-rich domain that requires multiple Sec incorporation events.Scope of review
In this review we elaborate on new data and current models that provide insight into how SELENOP is made.Major conclusions
SELENOP synthesis requires a specific set of factors and conditions.General significance
As the key protein required for proper selenium distribution, SELENOP stands out as a lynchpin selenoprotein that is essential for male fertility, proper neurologic function and selenium metabolism. 相似文献11.
V. Guru KrishnaKumar Lokesh Baweja Krittika Ralhan Sharad Gupta 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(12):2590-2604
Background
Carbamylation is a non-enzymatic post-translational modification (PTM), which involves the covalent modification of N-terminus of protein or ε-amino group of Lys. The role of carbamylation in several age-related disorders is well documented, however, the relationship between carbamylation and neurodegenerative disorders including Alzheimer's disease remains uncharted.Methods
In the present study, using aggregation-prone tau-core hexapeptide fragments 306VQIVYK311 (PHF6) and 275VQIINK280 (PHF6*) as models, we have elucidated the effect of carbamylation on aggregation kinetics and the changes occurring in the 3-dimensional architecture of fibrils using biophysical assays and molecular dynamics simulations.Results
We found that carbamylation aids in amyloid formation and can convert the unstructured off-pathway aggregates into robust amyloids, which were toxic to cells. Electron microscopy images and molecular dynamics simulations of PHF6 fibrils showed that carbamylated peptides can form excess hydrogen bonds and modulate the pitch length and twist of peptides fibrils. We have also compared N-terminal carbamylation to acetylation and further extended our finding to full length tau that exhibits aggregation upon carbamylation even in the absence of any external inducer.Conclusion
Our in vitro and in silico results together suggest that carbamylation can modulate the aggregation pathway of the amyloidegenic sequences and cause structural changes in fibril assemblies.General significance
Carbamylation acts as a switch, which triggers the aggregation in short amyloidogenic peptide fragments and modulate the structural changes in resulting amyloid fibrils. 相似文献12.
Rosa Gaglione Giovanni Smaldone Rocco Di Girolamo Renata Piccoli Emilia Pedone Angela Arciello 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):377-384
Background
Specific apolipoprotein A-I variants are associated to severe hereditary amyloidoses. The organ distribution of AApoAI amyloidosis seems to depend on the position of the mutation, since mutations in residues from 1 to 75 are mainly associated to hepatic and renal amyloidosis, while mutations in residues from 173 to 178 are mostly responsible for cardiac, laryngeal, and cutaneous amyloidosis. Molecular bases of this tissue specificity are still poorly understood, but it is increasingly emerging that protein destabilization induced by amyloidogenic mutations is neither necessary nor sufficient for amyloidosis development.Methods
By using a multidisciplinary approach, including circular dichroism, dynamic light scattering, spectrofluorometric and atomic force microscopy analyses, the effect of target cells on the conformation and fibrillogenic pathway of the two AApoAI amyloidogenic variants AApoAIL75P and AApoAIL174S has been monitored.Results
Our data show that specific cell milieus selectively affect conformation, aggregation propensity and fibrillogenesis of the two AApoAI amyloidogenic variants.Conclusions
An intriguing picture emerged indicating that defined cell contexts selectively induce fibrillogenesis of specific AApoAI variants.General significance
An innovative methodological approach, based on the use of whole intact cells to monitor the effects of cell context on AApoAI variants fibrillogenic pathway, has been set up. 相似文献13.
14.
Shreyasi Asthana Zaved Hazarika Parth Sarathi Nayak Jyoti Roy Anupam Nath Jha Bibekanand Mallick Suman Jha 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(1):153-166
Background
Injection localized amyloidosis is one of the most prevalent disorders in type II diabetes mellitus (TIIDM) patients relying on insulin injections. Previous studies have reported that nanoparticles can play a role in the amyloidogenic process of proteins. Hence, the present study deals with the effect of zinc oxide nanoparticles (ZnONP) on the amyloidogenicity and cytotoxicity of insulin.Methods
ZnONP is synthesised and characterized using XRD, Zeta Sizer, UV-Visible spectroscope and TEM. The characterization is followed by ZnONP interaction with insulin, which is studied employing fluorescence spectroscopes, isothermal titration calorimetry and molecular dynamics simulations. The interaction leads insulin conformational rearrangement into amyloid-like fibril, which is studied using thioflavin T dye binding assay, circular dichroism spectroscopy and TEM, followed by cytotoxicity propensity using Alamar Blue dye reduction assay.Results
Insulin has very weak interaction with ZnONP interface. Insulin at studied concentration forms amorphous aggregates at physiological pH, whereas in presence of ZnONP interface amyloid-like fibrils are formed. While the amyloid-like fibrils are cytotoxic to MIN6 and THP-1 cell lines, insulin and ZnONP individual solutions and their fresh mixtures enhance the cells proliferation.Conclusions
The presence of ZnONP interface enhances insulin fibrillation at physiological pH by providing a favourable template for the nucleation and growth of insulin amyloids.General significance
The studied protein-nanoparticle system from protein conformational dynamics point of view throws caution over nanoparticle use in biological applications, especially in vivo applications, considering the amyloidosis a very slow but non-curable degenerative disease. 相似文献15.
Xiu-Mei Wang Shi-Chao Fan Yao Chen Xiao-Feng Ma Rong-Qiao He 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(2):379-383
Background
Earthworms are widely used in basic and applied research in medicine, food, environment and agriculture, in which for instance earthworm protease has its own biochemical features.Scope of review
This review summarizes earthworm protease biochemical features in anti-thrombosis and anti-fibrosis, and provides new perspectives for earthworm to be used in biochemical and pharmaceutical studies.Major conclusions
Earthworm protease functions in anti-thrombosis by its fibrinolytic activity and inhibiting platelets aggregation, and anti-fibrosis by its decreasing fibronectin, collagen and laminin, showing a broad substrate specificity. The protease regulators (U3EE) from earthworm also has multiple functions acting as an activator and an inhibitor on different target proteins. Nonetheless, the protease improves the substrate selectivity through substrate-induced changes in the protease active site conformation impact on subsequent reactions with substrates.General significance
It is predictable that both biochemical and applied studies of earthworm proteins including protease will be wider and deeper in the future. 相似文献16.
Attilio Vittorio Vargiu Venkata Krishnan Ramaswamy Ivana Malvacio Giuliano Malloci Ulrich Kleinekathöfer Paolo Ruggerone 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):836-845
Background
Efflux pumps of the Resistance-Nodulation-cell Division superfamily confer multi-drug resistance to Gram-negative bacteria. The most-studied polyspecific transporter belonging to this class is the inner-membrane trimeric antiporter AcrB of Escherichia coli. In previous studies, a functional rotation mechanism was proposed for its functioning, according to which the three monomers undergo concerted conformational changes facilitating the extrusion of substrates. However, the molecular determinants and the energetics of this mechanism still remain unknown, so its feasibility must be proven mechanistically.Methods
A computational protocol able to mimic the functional rotation mechanism in AcrB was developed. By using multi-bias molecular dynamics simulations we characterized the translocation of the substrate doxorubicin driven by conformational changes of the protein. In addition, we estimated for the first time the free energy profile associated to this process.Results
We provided a molecular view of the process in agreement with experimental data. Moreover, we showed that the conformational changes occurring in AcrB enable the formation of a layer of structured waters on the internal surface of the transport channel. This water layer, in turn, allows for a fairly constant hydration of the substrate, facilitating its diffusion over a smooth free energy profile.Conclusions
Our findings reveal a new molecular mechanism of polyspecific transport whereby water contributes by screening potentially strong substrate-protein interactions.General significance
We provided a mechanistic understanding of a fundamental process related to multi-drug transport. Our results can help rationalizing the behavior of other polyspecific transporters and designing compounds avoiding extrusion or inhibitors of efflux pumps. 相似文献17.
Yuta Murakami Koichi Takahashi Kyoka Hoshi Hiromi Ito Mayumi Kanno Kiyoshi Saito Kenneth Nollet Yoshiki Yamaguchi Masakazu Miyajima Hajime Arai Yasuhiro Hashimoto Tatsuo Mima 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(8):1835-1842
Background
Spontaneous intracranial hypotension (SIH) is caused by cerebrospinal fluid (CSF) leakage. Definitive diagnosis can be difficult by clinical examinations and imaging studies.Methods
SIH was diagnosed with the following criteria: (i) evidence of CSF leakage by cranial magnetic resonance imaging (MRI) findings of intracranial hypotension and/or low CSF opening pressure; (ii) no recent history of dural puncture. We quantified CSF proteins by ELISA or Western blotting.Results
Comparing with non-SIH patients, SIH patients showed significant increase of brain-derived CSF glycoproteins such as lipocalin-type prostaglandin D synthase (L-PGDS), soluble protein fragments generated from amyloid precursor protein (sAPP) and “brain-type” transferrin (Tf). Serum-derived proteins such as albumin, immunoglobulin G, and serum Tf were also increased. A combination of L-PGDS and brain-type Tf differentiated SIH from non-SIH with sensitivity 94.7% and specificity 72.6%.Conclusion
L-PGDS and brain-type Tf can be biomarkers for diagnosing SIH.General significance
L-PGDS and brain-type Tf biosynthesized in the brain appears to be markers for abnormal metabolism of CSF. 相似文献18.
Joanna Strumillo Katarzyna E. Nowak Anita Krokosz Aleksandra Rodacka Mieczyslaw Puchala Grzegorz Bartosz 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(4):877-885
Background
Nitric oxide is a well-known gaseous signaling molecule and protein modifying agent. However, at higher concentrations or during oxidative stress nitric oxide may exert some deleterious effects on protein structure and function. Here we investigated the influence of nitric oxide and products of its oxidation on two glycolytic enzymes: GAPDH and LDH under in vitro nitrosative stress conditions. Secondly, we applied natural antioxidants: melatonin and resveratrol to examine their effects on the enzymes under studied conditions.Methods
By means of UV–VIS and fluorescence spectroscopy methods we compared nitric oxide mediated changes of enzyme activities, amount of free sulfhydryl groups (-SH) and bis-ANS probe binding. Finally, we predicted potential cysteine residues modified by nitric oxide in studied proteins using GPS-SNO software.Results
Our results indicated that nitric oxide reversibly inactivates GAPDH but does not affect the activity of LDH. Nitric oxide dependent GAPDH activity decline was accompanied by the reduction of the amount of free –SH groups and GAPDH-bound bis-ANS fluorescence. Reduction of the number of free –SH groups and protein-bound bis-ANS fluorescence was also observed in LDH treated with NO. Applied antioxidants increased inactivation of GAPDH and structural changes of GAPDH and LDH.Conclusions
Nitric oxide modifies function and structure of thiol-dependent enzyme such as GAPDH and structure of LDH which function do not rely on cysteine thiols. Both resveratrol and melatonin exerted prooxidative properties in studied conditions.General significance
Extensively studied antioxidants: resveratrol and melatonin may function as a prooxidative species under in vitro nitrosative stress conditions. 相似文献19.
Felista L. Tansi Ronny Rüger Ansgar M. Kollmeier Markus Rabenhold Frank Steiniger Roland E. Kontermann Ulf K. Teichgraeber Alfred Fahr Ingrid Hilger 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(6):1389-1400
Background
Endoglin (CD105) is overexpressed on tumor cells and tumor vasculatures, making it a potential target for diagnostic imaging and therapy of different neoplasms. Therefore, studies on nanocarrier systems designed for endoglin-directed diagnostic and drug delivery purposes would expose the feasibility of targeting endoglin with therapeutics.Methods
Liposomes carrying high concentrations of a near-infrared fluorescent dye in the aqueous interior were prepared by the lipid film hydration and extrusion procedure, then conjugated to single chain antibody fragments either selective for murine endoglin (termed mEnd-IL) or directed towards human endoglin (termed hEnd-IL). A combination of Dynamic Light Scattering, electron microscopy, cell binding and uptake assays, confocal microscopy and in vivo fluorescence imaging of mice bearing xenografted human breast cancer and human fibrosarcoma models were implemented to elucidate the potentials of the liposomes.Results
The mEnd-IL and hEnd-IL were highly selective for the respective murine- and human endoglin expressing cells in vitro and in vivo. Hence, the hEnd-IL bound distinctly to the tumor cells and enabled suitable fluorescence imaging of the tumors, whereas the mEnd-IL bound the tumor vasculature, but also to the liver, kidney and lung vasculature of mice.Conclusions
The work highlights key differences between targeting vascular (murine) and neoplastic (human) endoglin in animal studies, and suggests that the hEnd-IL can serve as a delivery system that targets human endoglin overexpressed in pathological conditions.General significance
The endoglin-targeting liposomes presented herewith represent strategic tools for the future implementation of endoglin-directed neoplastic and anti-angiogenic therapies. 相似文献20.
Yaroslav Staroseletz Sergey Nechaev Elena Bichenkova Richard A. Bryce Catherine Watson Valentin Vlassov Marina Zenkova 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(3):705-725