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DSC protein

Xuejiao Wang, Niamat Ullah, Xuchun Sun, Yan Guo, Lin Chen, Zhixi Li, Xianchao Feng
Biocomposite films were manufactured by combining protein extracted from buckwheat distiller's dried grains with bacterial cellulose (BC). The film microstructures showed that BC is compatible with protein matrix and endows the film with high rigidity. Differential scanning calorimetry (DSC) showed that BC can promote thermal stability of the composite films. BC promoted the transition from a Newtonian to a non-Newtonian fluid and the shear thinning behavior of protein-BC solution. Fourier Transform Infrared (FTIR) spectroscopy showed the main functional groups' absorption peaks shifted to lower wavenumbers...
November 28, 2016: International Journal of Biological Macromolecules
Sulabh Patel, Jan Olaf Stracke, Ulrike Altenburger, Hanns-Christian Mahler, Philipp Metzger, Pankaj Shende, Dhananjay Jere
Following intravitreal (IVT) injection, therapeutic proteins get exposed to physiological pH, temperature and components in the vitreous humor (VH) for a significantly long time. Therefore, it is of interest to study the stability of the proteins in the VH. However, the challenge posed by the isolated VH (such as pH shift upon isolation and incubation due to the formation of smaller molecular weight (MW) degradation products) can result in artefacts when investigating protein stability in relevance for the actual in vivo situation...
November 16, 2016: European Journal of Pharmaceutics and Biopharmaceutics
Diana P Gaspar, Carmen Serra, Paulo R Lino, Lídia Gonçalves, Pablo Taboada, Carmen Remuñán-López, António J Almeida
Associating protein with nanoparticles is an interesting strategy to improve their bioavailability and biological activity. Solid lipid nanoparticles (SLN) have been sought as carriers for therapeutic proteins transport to the lung epithelium. Nevertheless, because of their low inertia, nanoparticles intended for pulmonary application usually escape from lung deposition. To overcome this problem, the production of spray-dried powders containing nanoparticles has been recently reported. Herein we developed new hybrid microencapsulated SLN for pulmonary administration, containing a model protein (papain, PAP)...
November 15, 2016: International Journal of Pharmaceutics
Faranak Salmannejad, Nastaran Nafissi-Varcheh
This study is to investigate whether ectoines (ectoine and hydroxyectoine) can reduce aggregation of rhIFNα2b in aqueous solutions on thermal stress. The effect of thermal stress condition on the stability was therefore investigated using size exclusion-high performance liquid chromatography (SE-HPLC), different spectroscopic measurements, dynamic light scattering (DLS), electrophoresis, and differential scanning calorimetry (DSC). All experiments were performed in a sodium phosphate buffer system (100mM, pH7)...
November 11, 2016: European Journal of Pharmaceutical Sciences
Konstantin M Boyko, Tatiana V Rakitina, Dmitry A Korzhenevskiy, Anna V Vlaskina, Yuliya K Agapova, Dmitry E Kamashev, Sergey Y Kleymenov, Vladimir O Popov
The three-dimensional structure of the histone-like HU protein from the mycoplasma Spiroplasma melliferum KC3 (HUSpm) was determined at 1.4 Å resolution, and the thermal stability of the protein was evaluated by differential scanning calorimetry. A detailed analysis revealed that the three-dimensional structure of the HUSpm dimer is similar to that of its bacterial homologues but is characterized by stronger hydrophobic interactions at the dimer interface. This HUSpm dimer interface lacks salt bridges but is stabilized by a larger number of hydrogen bonds...
November 3, 2016: Scientific Reports
Shuyu Wang, Shifeng Yu, Michael S Siedler, Peter M Ihnat, Dana I Filoti, Ming Lu, Lei Zuo
We developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. This design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. We further demonstrated the performance of the sensor with lysozyme unfolding...
October 2016: Review of Scientific Instruments
Baiju P Krishnan, Rishika Rai, Aromal Asokan, Kana M Sureshan
Isosteric replacement of amide bond(s) of peptides with surrogate groups is an important strategy for the synthesis of peptidomimetics (pseudopeptides). Triazole is a well-recognized bioisostere for peptide-bond and peptides with one or more triazole units are of great interest for different applications. We have used a catalyst-free and solvent-free method viz. topochemical azide-alkyne cycloaddition (TAAC) reaction to synthesize pseudoproteins with repeating sequences. A designed β-sheet-forming L-Ala-L-Val dipeptide containing azide and alkyne at its termini (N3-Ala-Val-NHCH2C≡CH, 1) was synthesized...
October 28, 2016: Journal of the American Chemical Society
Vandana Dhaka, B S Khatkar
The gluten and its sub-fractions of good and poor bread quality wheat varieties were studied using scanning electron microscopy, differential scanning calorimetry (DSC) and IR spectroscopy techniques. The gluten of good bread quality wheat variety showed organized foam like matrix, whereas that of poor demonstrated an open gluten matrix. The glutenin of good bread quality wheat (HI 977) exhibited a more striated, organised texture in contrast to a dense, unorganised structure visible in C306. Gliadins of poor bread quality wheat were self-assembled to form a sheet like structure, whereas the gliadin proteins of good bread quality wheat variety showed more open microstructure...
August 2016: Journal of Food Science and Technology
Zhengrong Yang, Qingxian Zhou, Leo Mok, Anukriti Singh, Douglas J Swartz, Ina L Urbatsch, Christie G Brouillette
Structural changes in mouse P-glycoprotein (Pgp) induced by thermal unfolding were studied by differential scanning calorimetry (DSC), circular dichroism and fluorescence spectroscopy to gain insight into the solution conformation(s) of this ABC transporter that may not be apparent from current crystal structures. DSC of reconstituted Pgp showed two thermal unfolding transitions in the absence of MgATP, suggesting that each transition involved the cooperative unfolding of two or more interacting structural domains...
October 23, 2016: Biochimica et Biophysica Acta
Pakkawat Detchewa, Masubon Thongngam, Jay-Lin Jane, Onanong Naivikul
The objective of this study was to investigate the effect of soy protein isolate on functional properties and consumer acceptance of gluten-free rice spaghetti (GFRS) made from rice flour. Dry-milled high-amylose (Chai Nat 1) rice flour was premixed with dry-milled waxy (RD 6) rice flour at a ratio of 90:10 (w/w) with the soy protein isolate (SPI) concentration varying between 0, 2.5, 5.0, 7.5, 10.0 %, db. The GFRS formulation was processed using a co-rotating twin-screw extruder up to 95 °C with a screw speed of 220 rpm, 32 % moisture content, and then dried at 40 °C...
September 2016: Journal of Food Science and Technology
Sashka Krumova, Svetla Todinova, Deyan Mavrov, Pencho Marinov, Vassia Atanassova, Krassimir Atanassov, Stefka G Taneva
BACKGROUND: Biological microcalorimetry has entered into a phase where its potential for disease diagnostics is readily recognized. A wide variety of oncological and immunological disorders have been characterized by differential scanning calorimetry (DSC) and characteristic thermodynamic profiles were reported. Now the challenge before DSC is not the experimental data collection but the development of analysis protocols for reliable data stratification/classification and discrimination of disease specific features (calorimetric markers)...
October 15, 2016: Biochimica et Biophysica Acta
Mohammad Rehan Ajmal, Tajalli Ilm Chandel, Parvez Alam, Nida Zaidi, Masihuz Zaman, Saima Nusrat, Mohsin Vahid Khan, Mohammad Khursheed Siddiqi, Yasser E Shahein, Mohamed H Mahmoud, Gamal Badr, Rizwan Hasan Khan
Studying amyloid associated neurodegenerative diseases is an active area of research. Cure for these diseases are still to be discovered. In the present study we have performed comprehensive biophysical and computational experiments showing levodopa not only significantly inhibits heat induced fibrillization of human serum albumin but also disaggregates preformed fibrils. Thioflavin T (ThT) binding assay was used to monitor the fibrillation process of human serum albumin (HSA) at 65°C in the presence and absence of levodopa...
October 12, 2016: International Journal of Biological Macromolecules
José L Neira, Encarnación Medina-Carmona, José G Hernández-Cifre, Laia Montoliu-Gaya, Ana Cámara-Artigás, Ilham Seffouh, Florence Gonnet, Régis Daniel, Sandra Villegas, José García de la Torre, Angel L Pey, Fuchuan Li
Sulfatases catalyze hydrolysis of sulfate groups. They have a key role in regulating the sulfation states that determine the function of several scaffold molecules. Currently, there are not studies of the conformational stability of endosulfatases. In this work, we describe the structural features and conformational stability of a 4-O-endosulfatase (EndoV) from a marine bacterium, which removes specifically the 4-O-sulfate from chondroitin sulfate/dermatan sulfate. For that purpose, we have used several biophysical techniques, namely, fluorescence, circular dichroism (CD), FTIR spectroscopy, analytical ultracentrifugation (AUC), differential scanning calorimetry (DSC), mass spectrometry (MS), dynamic light scattering (DLS) and size exclusion chromatography (SEC)...
September 27, 2016: Biochimie
Kiran Deshmukh, Yuveraj Singh Tanwar, Shailendra Sharma, Pravin Shende, Roberta Cavalli
The aim of the present work was to develop lysozyme impregnated surface-active nanosponges to maintain its conformational stability and break bacterial cell walls by catalyzing the hydrolysis of 1,4-β-linkages between N-acetyl-d-glucosamine and N-acetylmuramic acid residues present in peptidoglycan layer surrounding the bacterial cell membrane, and for controlling the release of calcium in hypocalcemia condition. Different carbonyl diimidazole cross-linked β-cyclodextrin nanosponges with and without CaCO3 and CMC were prepared by polymer condensation method...
September 26, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Soher Nagi Jayash, Najihah Mohd Hashim, Misni Misran, N A Baharuddin
The osteoprotegerin (OPG) system plays a critical role in bone remodelling by regulating osteoclast formation and activity. The study aimed to determine the physicochemical properties and biocompatibility of a newly formulated OPG-chitosan gel. The OPG-chitosan gel was formulated using human OPG protein and water-soluble chitosan. The physicochemical properties were determined using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Gel morphology was determined using scanning electron microscopy (SEM) and then it was subjected to a protein release assay and biodegradability test...
September 29, 2016: Journal of Biomedical Materials Research. Part A
Qurat-Ul-Ain, Khalid Mahmood Zia, Fatima Zia, Muhammad Ali, Saima Rehman, Mohammad Zuber
Lipids are the main source of energy and widely used for various applications. In this review, the modification of lipids by using them in combination with other biomaterials like natural and synthetic polymers is elaborated. These new blends have characteristic features of both polymers and are characterized by different techniques (NMR, DSC, TGA, IR and Raman spectroscopy etc.) to understand their structure, properties and functional behavior. Lipids are hydrophobic, have anti-oxidant and anti-bacterial properties and thus impart hydrophobicity and flexibility to the polymers...
September 21, 2016: International Journal of Biological Macromolecules
Ziye Zhang, Yuling Yang, Peng Zhou, Xing Zhang, Jingyu Wang
The effects of high pressure (HP) treatment (100-500MPa) on conformation and gelation properties of myofibrillar protein (MP) were investigated. As pressure increased (0.1-500MPa), α-helix and β-sheet changed into random coil and β-turn, proteins unfolded to expose interior hydrophobic and sulfhydryl groups, therefore surface hydrophobicity and formation of disulfide bonds were strengthened. At 200MPa, protein solubility and gel hardness reached their maximum value, particle size had minimum value, and gel microstructure was dense and uniform...
February 15, 2017: Food Chemistry
Ruipu Xin, Suijian Qi, Chaoxi Zeng, Faez Iqbal Khan, Bo Yang, Yonghua Wang
In this study, the natural deep eutectic solvents (NADESs) based on trehalose and choline chloride have been prepared to enhance the protein thermostability. The results of fourier transform infrared spectroscopy and (1)H nuclear magnetic resonance spectroscopy suggested that there were intensive hydrogen-bonding interactions between trehalose and choline chloride in TCCL3-DES and TCCL3-DES75. The physicochemical properties of TCCL3-DES and TCCL3-DES75 were investigated in the temperature range of 293.15-363...
February 15, 2017: Food Chemistry
Nam Ah Kim, In Bok An, Hye Seong Lim, Sang In Yang, Seong Hoon Jeong
A newly developed hybrid Fc (hyFc) is a non-immunogenic and non-cytolytic Fc with intact Ig structure derived from human IgD and IgG4. It is fused with the human growth hormone (GXD-9) and was evaluated by various biophysical techniques. Two thermal transitions were evident by DSC, reflecting the unfolding of IgG4 and the conjugated protein. The highest Tm of the initial GXD-9 was 68.17°C and the Tm of the two domains were around 66°C and 70°C. Although Tm increased with decreasing concentration, which reflects increasing conformational stability, aggregation issues were still observed by DLS...
September 19, 2016: International Journal of Pharmaceutics
Joachim Seelig, Hans-Joachim Schönfeld
Thermally-induced protein unfolding is commonly described with the two-state model. This model assumes only two types of protein molecules in solution, the native (N) and the denatured, unfolded (U) protein. In reality, protein unfolding is a multistep process, even if intermediate states are only sparsely populated. As an alternative approach we explore the Zimm-Bragg theory, originally developed for the α-helix-to-random coil transition of synthetic polypeptides. The theory includes intermediate structures with concentrations determined by the cooperativity of the unfolding reaction...
January 2016: Quarterly Reviews of Biophysics
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