scholarly journals In situFTIR studies on mammalian cells

2010 ◽  
Vol 24 (5) ◽  
pp. 525-534 ◽  
Author(s):  
Willem F. Wolkers ◽  
Harriëtte Oldenhof
Keyword(s):  
Spectral Analysis ◽  
Phase Behavior ◽  
Mammalian Cells ◽  
Protein Denaturation ◽  
Cellular Systems ◽  
Membrane Phase ◽  
Helical Structures ◽  
Heating And Cooling ◽  
Stretching Vibration ◽  
Denaturation Of Proteins

In this work, we describe the application of FTIR spectroscopy to study lipids and proteins, in cellular systems during heating and cooling. Various spectral analysis methods are described to simultaneously study membrane phase behavior and heat-induced protein denaturation in cells. Membrane phase behavior was studied by following the temperature dependence of the CH2stretching vibration bands. Protein denaturation was studied using the amide-I and -III bands. Both amide-I and amide-III band analysis show that heat-induced denaturation of proteins within the cells is typically associated with an increase in extendedβ-sheet structures and a concomitant decrease in α-helical structures.

scholarly journals The Effects of Storage on Quality and Nutritional Values of Ehrenberg’s Snapper Muscles (Lutjanus Ehrenbergi): Evaluation of Natural Antioxidants Effect on the Denaturation of Proteins

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 442 ◽  
Author(s):  
Elgamouz ◽  
Alsaidi ◽  
Alsaidi ◽  
Zahri ◽  
Almehdi ◽  
...  
Keyword(s):  
Vitamin C ◽  
Protein Denaturation ◽  
Natural Antioxidants ◽  
Dsc Analysis ◽  
Nutritional Values ◽  
Sarcoplasmic Proteins ◽  
Stretching Vibration ◽  
Ft Ir ◽  
Denaturation Of Proteins

: Protein denaturation in frozen minced fillets (Ehrenberg’s Snapper), stored at −25°C was studied; 50.0 mg biomass/50g mince fillets treated with cinnamon, cumin, turmeric, garlic, ginger and 25.0 mg of vitamin C were used to slow protein denaturation. FT-IR stretching vibration of Amide-A (νNH) at 3300 cm−1; Amide-I stretching (νC=O) between 1600−1690 cm−1 and Amide-II stretching (νCN) and bending (δNH) between 1480 and 1575cm−1 were used as marker peaks. Garlic was the most significant (P ≤0.01) in controlling the rate of protein denaturation when νNH was used as a marker peak. DSC analysis showed that turmeric presented the highest effect on delaying the denaturation of sarcoplasmic proteins with a ∆H0=73.7J/g followed by garlic-treated mince fillets ∆H0=70.1J/g. All spices used were efficient in stopping the denaturation of myosin with the highest ∆H0=769.3 J/g registered for cinnamon-treated mince fillets. Actin was less vulnerable to denaturation in comparison to myosin and sarcoplasmic proteins.

37. Freeze Injury in mammalian cells predicted by membrane phase behavior

Cryobiology ◽  
2007 ◽  
Vol 55 (3) ◽  
pp. 336
Author(s):  
Saravana Kumar Balasubramanian ◽  
Kristen Bartelt ◽  
Willem Wolkers ◽  
John Bischof
Keyword(s):  
Phase Behavior ◽  
Mammalian Cells ◽  
Membrane Phase ◽  
Freeze Injury

Effect of Me2SO on Membrane Phase Behavior and Protein Denaturation of Human Pulmonary Endothelial Cells Studied by In Situ FTIR Spectroscopy

2009 ◽  
Vol 131 (7) ◽  
Author(s):  
Ralf Spindler ◽  
Willem F. Wolkers ◽  
Birgit Glasmacher
Keyword(s):  
Endothelial Cells ◽  
Phase Behavior ◽  
Wide Temperature Range ◽  
Protein Denaturation ◽  
Onset Temperature ◽  
Cellular Proteins ◽  
Membrane Phase ◽  
Conformational Disorder ◽  
Temperature Range ◽  
Pulmonary Endothelial Cells

Fourier transform infrared spectroscopy (FTIR) provides a unique technique to study membranes and proteins within their native cellular environment. FTIR was used here to study the effects of dimethyl sulfoxide (Me2SO) on membranes and proteins in human pulmonary endothelial cells (HPMECs). Temperature-dependent changes in characteristic lipid and protein vibrational bands were identified to reveal the effects of Me2SO on membrane phase behavior and protein stability. At Me2SO concentrations equal to or below 10% (v/v), Me2SO was found to decrease membrane conformational disorder. At higher Me2SO concentrations (15% v/v), however, membrane conformational disorder was found to be similar to that of cells in the absence of Me2SO. This effect was observed over a wide temperature range from 90°C down to −40°C. Me2SO had no clear effects on cellular proteins during freezing. During heating, however, Me2SO had a destabilizing effect on cellular proteins. In the absence of Me2SO, protein denaturation started at an onset temperature of 46°C, whereas at 15% Me2SO the onset temperature of protein denaturation decreased to 32°C. This implies that in the presence of Me2SO the onset temperature of protein denaturation is lower than the normal growth temperature of the cells, which could explain the well documented toxic effect of Me2SO at physiological temperatures. Me2SO destabilizes cellular proteins during heating and decreases membrane conformational disorder over a wide temperature range.

scholarly journals Down-modulation of Type 1 Interferon Responses by Receptor Cross-competition for a Shared Jak Kinase

2001 ◽  
Vol 276 (50) ◽  
pp. 47004-47012 ◽  
Author(s):  
Elisabetta Dondi ◽  
Els Pattyn ◽  
Georges Lutfalla ◽  
Xaveer Van Ostade ◽  
Gilles Uzé ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Transcriptional Response ◽  
Erythropoietin Receptor ◽  
Cellular Systems ◽  
Janus Kinase ◽  
Model Systems ◽  
Interleukin 12 ◽  
Interferon Α ◽  
Receptor Complexes

In contrast to the large number of class I and II cytokine receptors, only four Janus kinase (Jak) proteins are expressed in mammalian cells, implying the shared use of these kinases by many different receptor complexes. Consequently, if receptor numbers exceed the amount of available Jak, cross-interference patterns can be expected. We have engineered two model cellular systems expressing two different exogenous Tyk2-interacting receptors. A receptor chimera was generated wherein the extracellular part of the interferon type 1 receptor (Ifnar1) component of the interferon-α/β receptor is replaced by the equivalent domain of the erythropoietin receptor. Despite Tyk2 activation, erythropoietin treatment of cells expressing this erythropoietin receptor/Ifnar1 chimera did not evoke any detectable IFN-type response. However, a dose-dependent interference with signal transduction via the endogenous Ifnar complex was found for STAT1, STAT2, STAT3, Tyk2, and Jak1 activation, for gene induction, and for antiviral activity. In a similar approach, cells expressing the β1 chain of the interleukin-12 receptor showed a reduced transcriptional response to IFN-α as well as reduced STAT and kinase activation. In both model systems, titration of the Tyk2 kinase away from the Ifnar1 receptor chain accounts for the observed cross-interference.

Cryopreservation of platelets using trehalose: The role of membrane phase behavior during freezing

2012 ◽  
Vol 28 (5) ◽  
pp. 1347-1354 ◽  
Author(s):  
Christiane Gläfke ◽  
Maryam Akhoondi ◽  
Harriëtte Oldenhof ◽  
Harald Sieme ◽  
Willem F. Wolkers
Keyword(s):  
Phase Behavior ◽  
Membrane Phase

scholarly journals In situFTIR Assessment of Desiccation-Tolerant Tissues

2003 ◽  
Vol 17 (2-3) ◽  
pp. 297-313 ◽  
Author(s):  
Willem F. Wolkers ◽  
Folkert A. Hoekstra
Keyword(s):  
Secondary Structure ◽  
Desiccation Tolerance ◽  
Higher Plants ◽  
Protein Secondary Structure ◽  
Biological Tissues ◽  
Glassy Matrix ◽  
Vibration Band ◽  
Helical Structures ◽  
Ftir Studies ◽  
Stretching Vibration

This essay shows how Fourier transform infrared (FTIR) microspectroscopy can be applied to study thermodynamic parameters and conformation of endogenous biomolecules in desiccation-tolerant biological tissues. Desiccation tolerance is the remarkable ability of some organisms to survive complete dehydration. Seed and pollen of higher plants are well known examples of desiccation-tolerant tissues. FTIR studies on the overall protein secondary structure indicate that during the acquisition of desiccation tolerance, plant embryos exhibit proportional increases inα-helical structures and thatµ-sheet structures dominate upon drying of desiccation sensitive-embryos. During ageing of pollen and seeds, the overall protein secondary structure remains stable, whereas drastic changes in the thermotropic response of membranes occur, which coincide with a complete loss of viability. Properties of the cytoplasmic glassy matrix in desiccation-tolerant plant organs can be studied by monitoring the position of the OH-stretching vibration band of endogenous carbohydrates and proteins as a function of temperature. By applying these FTIR techniques to maturation-defective mutant seeds ofArabidopsis thalianawe were able to establish a correlation between macromolecular stability and desiccation tolerance. Taken together,in situFTIR studies can give unique information on conformation and stability of endogenous biomolecules in desiccation-tolerant tissues.

Osmotic properties and membrane phase behavior during cooling of stallion sperm

Cryobiology ◽  
2011 ◽  
Vol 63 (3) ◽  
pp. 310-311
Author(s):  
Harriëtte Oldenhof ◽  
Marina Gojowsky ◽  
Willem F Wolkers ◽  
Harald Sieme
Keyword(s):  
Phase Behavior ◽  
Membrane Phase ◽  
Osmotic Properties

scholarly journals Unusual Lower Critical Solution Temperature Phase Behavior of Poly(benzyl methacrylate) in a Pyrrolidinium-Based Ionic Liquid

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4850
Author(s):  
Brian R. Carrick ◽  
Claire L. Seitzinger ◽  
Timothy P. Lodge
Keyword(s):  
Ionic Liquid ◽  
Phase Behavior ◽  
Lower Critical Solution Temperature ◽  
Second Virial Coefficient ◽  
Coexistence Curve ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Strong Concentration ◽  
Critical Solution Temperature ◽  
Heating And Cooling

Polymer/ionic liquid systems are being increasingly explored, yet those exhibiting lower critical solution temperature (LCST) phase behavior remain poorly understood. Poly(benzyl methacrylate) in certain ionic liquids constitute unusual LCST systems, in that the second virial coefficient (A2) in dilute solutions has recently been shown to be positive, indicative of good solvent behavior, even above phase separation temperatures, where A2 < 0 is expected. In this work, we describe the LCST phase behavior of poly(benzyl methacrylate) in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide for three different molecular weights (32, 63, and 76 kg/mol) in concentrated solutions (5–40% by weight). Turbidimetry measurements reveal a strong concentration dependence to the phase boundaries, yet the molecular weight is shown to have no influence. The critical compositions of these systems are not accessed, and must therefore lie above 40 wt% polymer, far from the values (ca. 10%) anticipated by Flory-Huggins theory. The proximity of the experimental cloud point to the coexistence curve (binodal) and the thermo-reversibility of the phase transitions, are also confirmed at various heating and cooling rates.

scholarly journals Rapid zero-trans kinetics of Cs+ exchange in human erythrocytes quantified by dissolution hyperpolarized 133Cs+ NMR spectroscopy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Philip W. Kuchel ◽  
Magnus Karlsson ◽  
Mathilde Hauge Lerche ◽  
Dmitry Shishmarev ◽  
Jan Henrik Ardenkjaer-Larsen
Keyword(s):  
Nmr Spectroscopy ◽  
Mammalian Cells ◽  
Cellular Systems ◽  
Human Red Blood Cells ◽  
Technical Developments ◽  
Transport Studies ◽  
Transmembrane Flux ◽  
Free Media ◽  
Kinetics Of

AbstractTransmembrane flux of Cs+ (a K+ congener) was measured in human red blood cells (RBCs; erythrocytes) on the 10-s time scale. This is the first report on dissolution dynamic nuclear polarization (dDNP) nuclear magnetic resonance (NMR) spectroscopy with this nuclide in mammalian cells. Four technical developments regularized sample delivery and led to high quality NMR spectra. Cation-free media with the Piezo1 (mechanosensitive cation channel) activator yoda1 maximized the extent of membrane transport. First-order rate constants describing the fluxes were estimated using a combination of statistical methods in Mathematica, including the Markov chain Monte Carlo (MCMC) algorithm. Fluxes were in the range 4–70 μmol Cs+ (L RBC)−1 s−1; these are smaller than for urea, but comparable to glucose. Methodology and analytical procedures developed will be applicable to transmembrane cation transport studies in the presence of additional Piezo1 effectors, to other cellular systems, and potentially in vivo.

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